Human Variation Exam #1
Has the Sahara Desert always been a desert? What was that region like several thousand years ago? At the LGM?
The Sahara Desert has not always been a desert. Several thousand years ago, the region now covered by the Sahara was a savannah with a diverse range of plant and animal life. At the last glacial maximum (LGM) about 20,000 years ago, the Sahara was a much wetter and greener place, with lakes, rivers, and grasslands that supported a wide range of animals, including elephants, giraffes, and antelopes, as well as humans. During the LGM, the Sahara was much cooler and wetter than it is today, and the region received much more rainfall. This was due to changes in global climate patterns, including changes in the Earth's orbit, which affected the amount and distribution of sunlight reaching different parts of the planet. As a result, the Sahara was transformed into a much more hospitable environment, with large lakes and rivers that supported a thriving ecosystem. However, as the climate began to warm, the Sahara gradually began to dry out, and over time it became the arid desert that we know today.
What were Darwin's two major contributions to our understanding of the natural world from "The Origin of Species"?
The Theory of Evolution where natural selection is the mechanism that drives evolution, and the Descent with Modification, which suggests that all living things on Earth are descended from a common ancestor
what were the earliest humans in Europes lifestyle and technology like?
The earliest anatomically modern humans (AMH) in Europe are believed to have arrived around 45,000-43,000 years ago, during the Upper Paleolithic period. They were characterized by the development of new stone tool technologies, such as blade and burin technology, which allowed for more efficient and specialized hunting and gathering practices. AMH in Europe during the Upper Paleolithic period were also known for their cave art and figurative art, which suggests the development of symbolic and cultural behaviors. They were hunter-gatherers, and their lifestyle would have been dependent on their environment and seasonal changes, with mobility being an important aspect of their survival strategy.
Copernicus?
a Polish astronomer who lived in the 16th century and is famous for his heliocentric model of the solar system which challenged the geocentric model of the universe that had been widely accepted at the time.
Theosodius Dobzhansky
a Ukrainian-American geneticist and evolutionary biologist who is best known for work on the genetics of natural populations and his articulation of the principle that genetic variation is the raw material upon which natural selection acts, experimented on fruit fly. Argued that the process of evolution is driven by the interaction between genetic variation and natural selection. Also wrote about role of culture and language in shaping human evolution, and helped establish field of evolutionary anthropology
What is higher criticism?
a field of biblical scholarship that focuses o the historical and literary analysis of the Bible, that emerged in the 19th century as part of the Enlightenment
What is uniformitarianism?
a geological principle that was first proposed by James Hutton and later expanded by Charles Lyell, it is the idea that processes and forces that shaped the Earth's surface in the past are the same processes and forces that continue to operate today and that they operate at a relatively uniform and consistent rate over time.
What is pleiotropy?
a phenomenon in genetics where a single gene affects multiple traits,
What is parsimony?
a principle that suggests the simplest explanation or solution is often the best one, also known as Occam's razor
What is the Universal Genetic Code?
a set of rules by which DNA and RNS sequences are translated into the amino acid sequences of proteins, shared by almost all living organisms, indicating that it has been conserved throughout the course of evolution
What is paleoanthropology?
a subfield of anthropology that studies the biological and cultural evolution of humans and their ancestors over time. It is the study of physical remains, artifacts, and cultural practices of early humans and their extinct relatives
What is binomial nomenclature?
a system of naming species in which each species is given a unique scientific name consisting of two parts: the genus and species, first developed by Linnaeus, hierarchal system of classification is known as taxonomy
What is a genus?
a taxonomic rank used to classify organisms that are closely related and share common characteristics
What is a conspecific?
a term used in biology to refer to individuals or groups of the same species, used to describe the relationship between organisms of the same species as opposed to individuals or groups of different species
What is the Scala naturae
also known as "Great Chain of Being" a medieval and early modern concept that suggests that living things are part of a hierarchal system, which each species occupying a specific place on a ladder-like scale of nature, seen now as a relic of the past
Thomas Malthus
an 18th and 19th century British economist and demographer, best known for his theories on population growth and its relation to resources and food supply.
Jean-Baptiste Lamarck?
an 18th and 19th century French naturalist, best known for theory of evolution which he developed before Darwin's publication "On the Origin of Species." He believed in the idea of "inheritance of acquired characteristics" which is no longer considered accurate but he was one of the first scientists to propose the species change over time
Carolus Linnaeus
an 18th century Swedish botanist, zoologist, and physician, considered the father of modern taxonomy, created the Linnaean Hierarchy, and established a species and genus for every species on thematic similarities. He placed humans at the top of the chain of nature but noted tmore than one link separated humans from those immediately below, now considered outdated and his classifications were broad generalizations
Thomas H Morgan
an American geneticist who made significant contributions to the study of human variation thru his work on the fruit fly, to study how traits are inherited and how they are linked to specific genes, he discovered sex-linked inheritance, where traits are determined by genes located on X or Y chromosome. also discovered that some traits, like eye color, are controlled by multiple genes and the physical location of genes on chromosomes can influence how they are inherited
Gregor Mendel
an Austrian monk who lived in the 19th century, known as the father of modern genetics. thru his experiments with pea plants, he discovered the basic principles of inheritance which form the foundation of our understanding. of how traits are passed down from generation to the next. He discovered dominance, recessiveness, segregation, and independent assortment
Isaac Newton?
an Eng;ish physicist who lived in 17th and early 18th centuries, best known for his laws of motion and universal gravitation. His work helped to establish a more rigorous and systematic approach to scientific inquiry
Galileo Galilei?
best known for his telescopic observations of the moons of Jupiter, phases of Venus, and sunspots on Sun. He challenged the prevailing view of the cosmos as static and unchanging and argued Earth was not the center of the universe.
mRNA
carries genetic info from the DNA in nucleus of a cell to the ribosomes where it is translated into proteins, the sequence of nucleotides in this determines the the sequence of amino acids in the protein that is synthesized, a critical component of gene expression and abonormalities in its function can lead to various disease
What are the four fields of anthropology
cultural anthropology, archaeology, linguistic anthropology, biological/physical anthropology
what does the geographical distribution of archaic Homo sapiens suggest about modern human variation?
it suggests that modern human variation is the result of multiple waves of migration and genetic exchange between different human populations over time. archaic homo sapiens were the ancestors of modern humans who lived before the emergence of anatomically modern humans in Africa about 300,000 years ago
how were modern humans different from earlier humans
modern homo sapiens have a more rounded skull, smaller brow ridges, a more vertical forehead, smaller face and jaws, and more slender build, larger brain size and more cognitive abilities, more complex cultures and technologies, and more complex social behavior
where and when did modern humans originate?
modern humans, are believed to have originated in Africa approximately 300,000 years ago
rRNA
one of the three main types of RNA involved in protein synthesis, because rRNA sequences are highly conserved and are present in all living organisms, they can be used to contract phylogenetic trees and infer evolutionary relationships between diff species
tRNA
plays a crucial role in protein synthesis, transfers aminos acids to the ribosome during protein synthesis, where amino acids are linked together to form a polypeptide chain, ensures that each amino acid is added to the protein the correct sequence, mutations in this can lead to a variety of genetic diseases
What is vestigial?
refers to a structure or organ in an organism that has lost all or most of its original function but is still present in the body
What were Darwin's three major problems with his theory of natural selection?
the problem of incomplete fossil record, the problem of blending inheritance, the problem of the origin of variation
What is biogegraphy?
the scientific study of the distribution of living organisms on Earth both in terms of their geographic location and their evolutionary history, seeks to answer how different species of plants and animals have come to be distributed across the planet, includes studying plate tectonics, climate change, and formation of barriers that separate diff regions
What is paleontology?
the study of the history of life on Earth, based on the study of fossils and other evidence of ancient life
Francis Crick and James Watson
two of the most famous molecular biologists of 20th century, they proposed the now-famous double helix model of DNA, made possible by the earlier work of Rosalind Franklin and Maurice Wilkins
Comte de Buffon?
was one the first scientists to attempt to systematically classify living organisms, but believed different human populations were fixed and immutable
what is th effect of climate changes on the regions occupied by modern humans during the last 130,000 years from the origin of the last ice age to the present?
Climate changes during the last 130,000 years have had a significant impact on the regions occupied by modern humans. During the last ice age, which lasted from around 115,000 to 11,700 years ago, much of the northern hemisphere was covered in ice, causing sea levels to drop and exposing land bridges between continents. This allowed humans and other animals to migrate to new areas.As the ice sheets retreated and sea levels rose, some areas became uninhabitable, while others opened up for human settlement. For example, the warming climate in the Middle East around 50,000 years ago may have encouraged humans to move into the region, where they developed agriculture and civilization. Similarly, the warming climate in Europe around 10,000 years ago allowed humans to expand their range and develop new technologies.
what and where are the European refugia?
During the Last Glacial Maximum (LGM), which occurred between 26,500 and 19,000 years ago, much of Europe was covered by ice sheets and glaciers. However, there were a few areas in southern Europe that remained relatively ice-free, and these areas served as refugia for plants and animals that were adapted to warmer conditions. Some of the main European refugia were located in the Iberian Peninsula (Spain and Portugal), the Italian Peninsula, and the Balkan Peninsula (Greece and parts of the Balkan countries). These areas provided a refuge for many species during the cold and dry conditions of the LGM. As the climate warmed after the LGM, these species gradually expanded their ranges back into the rest of Europe. It is also thought that these refugia may have played a role in the survival and eventual expansion of human populations during and after the LGM, as these areas would have provided a more habitable environment than the ice-covered regions to the north.
what happened to the AMH in Europe as the glaciers advanced?
During the last glacial maximum, which occurred between about 26,500 and 19,000 years ago, much of northern Europe was covered by ice sheets and the climate was extremely cold and dry. This would have made it difficult for humans to survive in the region, and it is likely that they retreated to southern refugia such as Iberia and the Balkans. When the ice began to retreat, humans gradually moved back into northern Europe, probably following the receding glaciers and the newly opened habitats that emerged as a result. The first humans to re-colonize northern Europe were likely to have been hunter-gatherers who relied on a variety of resources for their survival, including fish, game, and plant foods. They would have used a range of stone tools and other technologies to hunt, gather, and process their food, and they may have lived in small groups or bands. Over time, these groups may have developed more complex social structures and technologies, leading to the development of the cultures that are known from the later prehistoric and historic periods.
John Ray?
English naturalist and botanist in the 17th century, he recognized the existence of different human populations but his classification was flawed bc he considered European populations to be the most advanced and tried to justify the subordination of other races.
Sir Francis Bacon?
English scientist of 16th and 17th centuries, he introduced induction, looking at the real world, argued that the scientific method could be used to uncover knowledge about humans and could overcome superstition and judgement
Einstein?
(1915), his General Theories of Relativity, some scientists tried to associate his theories to argue for inherent physical differences between human populations but now we know race is just a social construct, no biological basis.
what is the order in which humans reach different geographical regions and what are the routes and sequences of these dispersals?
1. out of Africa, around 60,000 years ago 2. asia: from Africa thru the Arabian peninsula, across Indian subcontinent, and into Southeast Asia, 3. Australia and New Guinea: humans reached Australia and New Guinea about 50,000 years ago, either by land bridges or using watercraft 4. europe: around 45,000 years ago humans arrived in Europe either by crossing mediterranean or traveling northward thru Middle East and into Central Asia then into europe 5. asia (again): humans likely migrated further into the continent after first migration into Asia, eventually reaching china 6. the americas were the last major region to be colonized by humans likely sometimes between 20,000 to 15,000 years ago
Charles Lyell?
A British geologist of the 19th century, known for his work on the principle of uniformitarianism, which is the idea that the processes that shape Earth today are there same processes that have been at work thru all history. This established a framework of understanding the long-term processes that have shaped the diversity of life on Earth.
James Hutton?
A Scottish geologist of the 18thcentury, "the father of modern geology," he believed that Earth was shaped by slow and gradual processes, rather than sudden and catastrophic events. His ideas contributed to the theory of evolution, which proposed that living organisms had evolved over time in response to changing environmental conditions.
How is the Great Chain of Being different from Aristotle' view?
Aristotle believed that living things could be arranged in a hierarchy based on their complexity, but he did not see this as fixed or divinely ordained, he believed that the hierarchy could change over time as new species evolved
what happened to the distribution of human populations as the climate warmed?
As the climate warmed and the glaciers receded, human populations also shifted and expanded their ranges. Some populations that had been restricted to refugia during the Last Glacial Maximum were able to spread out and recolonize other areas. For example, humans began to spread northwards from the Iberian refugium in southwestern Europe around 16,000 years ago, eventually reaching northern Europe and Scandinavia. Meanwhile, other populations from the Balkans and Anatolia expanded westward into central Europe. In general, as the climate became warmer and wetter, forests and other vegetation expanded, which allowed for a more diverse range of animal and plant species to thrive, providing more food resources for humans to exploit.
What was Aristotle's contribution to the study of human variation?
He recognized that there were variations in physical characteristics within species, and he attempted to categorize and describe these variations. He also explored the factors that could contribute to this variation, including geographical location, climate, and environmental conditions. He also provided a detailed analysis on human anatomy and behavior. Created nature's scale and Was considered ultimate authority until church in 5th century.
How did the last Ice Age change the distribution of plants and animals (including humans, of course) in Africa? In Europe?
In Africa, the Ice Age was less severe than in Europe, and the Sahara Desert expanded, creating barriers to movement and leading to the isolation of populations. The desertification of the Sahara forced many human populations to move to other areas, such as the Nile Valley, where the climate was more hospitable. In Europe, the Ice Age caused a major shift in the distribution of plants and animals, as many species moved south to warmer areas. This included the human population, which moved south as the glaciers advanced. The warmer areas in the south, such as the Iberian Peninsula and the Balkans, became refugia for many species, including humans. As the climate warmed, the glaciers retreated, and the human population expanded northward, recolonizing areas that had been uninhabitable during the Ice Age. This expansion was facilitated by advances in technology, such as the development of agriculture.
when did modern humans first show up in europe?
Modern humans, or Homo sapiens, first showed up in Europe around 45,000 years ago during the Upper Paleolithic period. The first evidence of their presence comes from archaeological sites in what is now Bulgaria and Italy, and they gradually spread across the continent. The exact timing and route of their dispersal into Europe is still a subject of ongoing research and debate.
what was europe like during the Last Glacial Maximum?
The last glacial maximum occurred about 26,500 to 19,000 years ago and was the peak of the last ice age. During this time, large parts of Europe were covered in ice sheets and glaciers, and much of the rest of the continent was a tundra environment, with dry and cold conditions. The climate was much colder and drier than today, and sea levels were significantly lower due to the amount of water that was locked up in glaciers. Many plant and animal species were adapted to the cold and dry conditions, including woolly mammoths, reindeer, and other cold-adapted mammals, as well as many species of plants that were able to survive in the harsh climate. Human populations that lived in Europe at this time, such as the Cro-Magnon people, were also adapted to the cold environment, and had developed sophisticated hunting and gathering techniques to survive in the harsh conditions.
when was the peak of the last Ice Age and what effect did the last Ice Age have on modern humans and our current geographical distribution?
The peak of the last Ice Age occurred about 20,000 years ago. The last Ice Age had a significant effect on modern humans and their distribution. As the glaciers advanced, many areas that were previously inhabited by humans became uninhabitable, leading to a contraction in the range of human populations. During this time, humans in different parts of the world developed unique adaptations to the cold, such as the lighter skin color of people in northern latitudes, which allowed for increased vitamin D production in areas with reduced sunlight. As the climate began to warm again, some human populations began to expand their ranges and colonize new areas. This led to the development of a diverse range of cultures and societies across the globe, each adapted to their unique environments.
Robert Hooke
a 17th century English scientist best known for his invention of the compound microscope which allowed him to observe and study the smallest structures and organisms in detail
Charles Darwin
a 19th century British naturalist and biologist who is best known for his theory of evolution by natural selection, based on the idea that individuals within a population vary in their inherited traits, and those with advantageous traits are more likely to survive and reproduce. Known for his Galapagos Finches
Thomas Huxley?
a British biologists who lived in the 19th century. He is known as "Darwin's Bulldog" for his staunch defense of Darwin's theory of evolution. He was a strong proponent of the idea that all living organisms were descended from a common ancestor
Alfred Wallace?
a British naturalist of the 19th century, who contributed to the theory of evolution, which he independently developed outside of Charles Darwin. He sent a letter to Darwin in 1858, outlining his ideas on natural selection, the two men jointly presented their work to the scientific community.
Johannes Kepler?
a German astronomer who lived in 16th and early 17th century, best known for his laws of planetary motion, which established a more accurate understanding for the universe