Evolution and Population - BIO 1107
analagous structures
body parts with a similar function, but different structures. They do not show common ancestry. Ex: butterfly wing and bat wing
Homo erectus
"Upright man" This hominin had an even larger brain, a flatter face and was the first to use fire, these may also have been the first to use language. 1.8 million to 300,000 years ago. Also first hominin to venture out of Asia. (may also be called Homo ergaster if descended from African lineage) They made more difficult and better made tools.
Homo habilis
"handy man" About 2 million years ago some hominins were making tools. These may have been the earliest humans. Compared to australopiths, these early species had a smaller face, smaller teeth, and a larger brain. These were also the first hominins to establish cultural aspects to their lives and had speech.
biochemical evidence for evolution
- Almost all living things use the same biochemicals (DNA, ATP, Enzymes) - Living things use the same triplet code in DNA - Living things use the same 20 amino acids in their proteins - Living things share many of the same genes
Human contribution to air pollution
- Emissions from industries and manufacturing activities - Burning Fossil fuels - Household and Farming Chemicals - Oxides of sulfur and nitrogen are among the most dangerous air pollutants - Coal burning power plants, factories, metal smelters, vehicles, power plants and nitrogen fertilizers are the main sources of these oxides (contributors to greenhouse gases)
Evidence to support the theory of evolution by common descent
- Fossils in the fossil record - Biogeographical evidence - Anatomical evidence - Biochemical evidence
characteristics of primates
- Opposable thumb - Stereoscopic vision (depth perception) - Well-developed brain - Reduced # of offspring (usually a single birth) with an increased period of parental care - Emphasis on learned behavior and social interactions Two suborders: Prosimians - includes lemurs, tarsiers, and lorises Anthropoids - includes monkeys, apes, and humans
What have we learned from the fossil record?
- They tell us that life progressed from simple to more complex - Prokaryotes are the first life forms seen, followed by unicellular eukaryotes and then multicellular eukaryotes - Fishes evolved before terrestrial plants and animals - Nonflowering plants preceded flowering plants - Amphibians preceded reptiles - Dinosaurs are directly linked to birds
neanderthals
-believed to be an offshoot of homo sapien descent. -They may have coexisted and even interbred with the homo sapiens. -About 200,000 years ago, during last ice age. -They disappeared about 35,000-40,000 years ago -built houses, controlled fire, had burial ceremonies -(1-4% of the genomes of non-african homo sapiens contain remnants of neandertal genome)
characteristics of Homo
1. Brain size is 600 cm3 or greater 2. Evidence of tool use 3. Jaw and teeth resemble humans Early Homo representatives: - Homo habilis - Homo erectus Later Homo representatives: - Neanderthals - Cro-Magnons
four stages that lead to the first living cells
1. Monomers 2. Polymers 3. Protocells 4. Living cells
adaptation
A characteristic that makes an organism able to survive and reproduce in its environment It help explain the diversity of life (why there are so many different types of living organisms).
Australopithecines
A group of hominins that evolved and diversified in Africa 3-5 MYA - Some had slight frames and others were robust with massive jaws that fed on plant materials - Walked upright - Limbs proportions are ape-like - Small brain - Famous skeleton named "Lucy" is from this group - Australopithecus africanus has a large brain is the most likely ancestral candidate for early Homo
hominid
A hominid is a member of the family Hominidae, the great apes: orangutans, gorillas, chimpanzees and humans.
ozone layer
A layer in the stratosphere (at approximately 20 miles) that contains a concentration of ozone sufficient to block most ultraviolet radiation from the sun.
Hominid
A member of a biological group including human beings and related species that walk upright. - Apes are more similar to humans than monkeys, so humans and apes are further classified as Hominids (gorillas, orangutans, chimpanzees and humans) -The term Hominine is now used to include only the gorillas, chimps and humans. -Hominin refers to all members of the genus Homo and their close relatives. -Bipedal stature is the hallmark of the hominin group.
over farming
A situation in which land is repeatedly farmed so that the soil nutrients are depleted
Cytochrome c
A small protein ,common in many living organisms, used for genetic relation. It plays an important role in the electron transport chain within mitochondria of all cells.
water use (natural resource)
Agriculture uses most of the freshwater that is consumed. Industrial use of water is about half the amount of agricultural use. Domestic use of water is about half the amount of industrial use. - 70% of freshwater worldwide is used for irrigation of crops - In MDCs more water is used for bathing, toilets, and watering lawns than for drinking and cooking - Dams change the flow of rivers, lose a lot of water, and can be filled in by sediment
opposable thumb
An arrangement of the fingers such that the thumb can touch the ventral surface of the fingertips of all four fingers. It enables grasping objects and using tools
human enhanced greenhouse effect
An increase of greenhouse gasses in the atmosphere causes less heat to escapes into space, and more heat to be re-emitted.
vestigial structures
Anatomical features fully developed in one group but are reduced and may have no function in another group. E.g. whales have a vestigial pelvic girdle and legs
anatomical evidence of evolution
Anatomical similarities lends further weight to common descent..
homologous structures
Anatomically similar structures that are inherited by a common ancestor. E.g. vertebrate forelimbs
pollution
Any undesired alteration of the environment. It is often caused by human activities or use of resources.
biological evolution
Change in population or species over time, it has two important aspects: 1. Living things descended from a common ancestor and thus have common chemistry 2. Livings things adapt to their environment
Hydrofluorocarbons (HFCs)
Chemicals containing hydrogen, fluorine, and carbons, produced as potential substitutes for CFCs While they are only weak ozone-depleting substances, they are, like CFCs and HCFCs, strong greenhouse gases. If production trends continue, projections show that, by 2050, the amount of global warming by all HFCs could be as large as 20 percent that of carbon dioxide
CFCs (chlorofluorocarbons)
Chemicals used in coolants, solvents, aerosol cans, and for other industrial uses, that are largely responsible for ozone depletion.
desertification
Degradation of land, especially in semiarid areas, primarily because of human actions like excessive crop planting, animal grazing, and tree cutting.
habitat loss
Destruction or disruption of Earth's natural habitats, most often due to human actions such as agriculture, forestry, mining, and urbanization
Age structure in MDCs (more developed countries) and LDCs (less developed countries)
Even though the world's growth rate has slowed down, the population will continue to increase because more women are entering the reproductive years than leaving them especially in less developed countries.
the beginning of agriculture
Farming may have begun at the end of the last ice age as large game became increasingly extinct, fertile land was exposed and weather warmed. Hunter gatherers would have already known proper seed selection. Farming lead to sedentary lifestyles rather than nomadic, enlarging families and requiring more food for larger populations. This caused a rapid increase of human numbers all over the earth.
transitional fossils
Fossils that have characteristic of two different groups. They tell us who is related to whom and how evolution occurred. Tiktaalik roseae or "fishapod" is a transitional form found in 2004 between fish and four legged animals. Archaeopteryx: transition between reptiles and birds Ambulocetus natans: transition between terrestrial ancestors and whales
What are humans?
Homo sapien (Latin for wise man); A species of mammals in the order primates. Primates have mobile limbs, grasping hands, a flattened face, binocular vision, complex brain and reduced reproductive rates. Together with chimpanzees, gorillas, and orangutans, they are part of the family Hominidae (the great apes, or hominids). They are member of the subfamily Homininae, which includes the African apes and humans. Humans (Homo sapiens) are the only extant (non-extinct) members of the subtribe Hominina.
What is considered a modern human?
Homo sapiens. All people living today belong to the species Homo sapiens. We evolved only relatively recently but with complex culture and technology have been able to spread throughout the world and occupy a range of different environments.
Which primate are we most closely related to?
Humans share about 99% of our DNA with chimpanzees, making them our closest living relatives
human population growth
If the birth rate is greater than the death rate by a consistent amount, the population will grow exponentially. Exponential curves like growth occur as one variable increases much faster than another variable (number of individuals increasing faster than time). Less developed countries have far greater rates of population growth.
carrying capacity
Largest number of individuals of a population that a environment can support
Cro-Magnons
Lived about 40,000 to 10,000 years ago Oldest fossils to be designated Homo sapiens - The first to be classified as modern humans, these hominins hunted in complex groups and established family groups. - Advanced culture including art, tool and maybe language - Good cooperative hunters They were likely to have been the first to use speech to any great extent.
Population growth in more developed and less developed countries
MDCs have a low population increase averaging ~0.1% (US is ~0.6%) LDCs are having a 1.6% growth rate but some countries (most in Africa/Asia) are increasing at a much higher rate Even though the world's growth rate has slowed down, the population will continue to increase because more women are entering the reproductive years than leaving them.
hominine
Member of the subfamily Homininae, which includes the African apes and humans A hominine is a member of the subfamily Homininae: gorillas, chimpanzees, and humans (excludes orangutans).
key trends in human evolution
More and more, DNA evidence is helping to trace the history of life, including the last common ancestor for the apes and humans. This last possible link may have occurred about 7 MYA. Humans and apes are 90% similar in their genes (think "cousin"), so shows considerable variation, but have been evolving separately for these 7 million years.
Hox genes
Morphology or development genes that are shared in many animals including humans and worms for example. They controls the differentiation of cells and tissues in an embryo.
Degradation of land
Natural or human-induced reduction in the potential ability of the land to support crops or livestock.
natural greenhouse effect
Natural situation in which heat is retained in Earth's atmosphere by carbon dioxide, methane, water vapor, and other gases
Stage 3: Protocells
Organic polymers became enclosed in a membrane to form the first cell precursors, called protocells or probionts. They could not replicated and were not alive. If you mix lipids in water they will join together to form spheres that could have acted as cell membranes if they formed around the proteins and nucleic acids.
fossils
Preserved remains of once-living organisms. They remain one of the best sources of evidence for evolution. They are the actual remains of species that lived on Earth at least 10,000 years ago, up to billions of years ago. Decisions about the history of life, ancient climates, and environments can be made using the fossil record.
acid rain
Rain containing a weak solution of sulfuric acid and nitric acid which forms in the atmosphere when industrial gas emissions (especially sulfur dioxide and nitrogen oxides) combine with water. Winds can distribute them over great distances before they fall to earth in rain and snow. When they fall to earth, they can lower pH of bodies of water and ground. It can kill plant life, pollute rivers and streams, and erode stonework.
renewable resources
Resources that are able to be replenished naturally. Examples include; water, plants, and animals for food and solar energy.
nonrenewable resources
Resources that are limited in supply. Examples include; amount of land, fossil fuels, and minerals.
pollutants
Substances which adversely affect the survival, activities and health of a population. Every day, the atmosphere receives more than 700,000 metric tons of pollutants from the U.S. alone.
Stage 1: Monomers
The abiotic synthesis of small organic molecules, like amino acids and nitrogenous bases. The carbon, hydrogen, oxygen, nitrogen, sulfur, atoms needed to make small organic molecules came from the gases in the atmosphere that came out of the earth during differentiation. The energy needed to make these molecules abiotically could have come from sunlight, heat, and lightning.
Australopithecus afarensis
The famous "lucy" the first to walk totally bipedally, these hominids were believed to have resembled humans below the waist and chimps above the waist. Lucy lived 3.2 million years ago.
dispersion
The general pattern in which the population's members are distributed throughout the habitat
Stage 2: Polymers
The joining of these smaller molecules into larger polymers, like proteins and nucleic acids. This could occur in small warm earth surface pools as the small molecules got closer together.
mortality rate
The number of deaths per year. Death rate is how mortality is usually described for human populations.
natality rate
The number of individuals added to the population through reproduction. Birth Rate is how natality is usually described for human populations.
age distribution
The number of individuals of each age in a population.
population density
The number of individuals per unit area or volume
Stage 4: Living Cells
The origin of self replicating molecules, that eventually made inheritance possible (passing on of genetic information to offspring) The RNA World is a time when RNA acted as a genetic instructions and the builder of proteins. Ribozymes are an example of this in today's cells.
ecological footprint
The total amount of resources used by an individual to meet their needs.
biotic potential
The population's maximum rate of growth under ideal conditions. Exponential growth usually would indicate a population is reaching its biotic potential. Growth begins to decline because of limiting factors. The carrying capacity of the earth for humans has not been determined, though some think the earth may be able to sustain 50-100 billion people, while others believe we have already reached our limit.
troposphere
The region of the earth's atmosphere closest to the earth's surface. Ozone is a component of smog and can be very damaging to human resp. tract and plant life.
sex ratio
The relative numbers of males to females (even minor differences can be important). In humans, about 106 males are born to every 100 females.
deforestation
The removal of trees faster than forests can replace themselves. It can lead to infertile agricultural or grazing land as well as loss of biodiversity.
stratosphere
The second atmospheric layer, ozone intercepts harmful ultraviolet radiation that can cause skin cancer and eye cataract in humans and can severely damage other organisms. This protective screen has been thinning.
population dynamics
The study of short‐ and long‐term changes in the number of individuals for a given population, as affected by birth, death, immigration, and emigration.
biogeographical evidence
The study of the distribution of plants and animals throughout the world. Supports the hypothesis that organisms originate in one locale and then may spread out. Diversity occurred later as adaptation to their environment took place.
Hominini (hominins)
The tribe of bipedal primates which includes the australopithecines, paranthropines, and all species of the genus Homo. Humans (Homo sapiens) are the last surviving hominin lineage. A member of the primate family Hominidae, distinguished by bipedal posture and, in more recently evolved species, a large brain. A member of the tribe Hominini.
Australopithecus africanus and africanus robustus (also called paranthropus robustus)
These hominids had more human-like hands and even had opposable thumbs. These possible human descendants lived about 2.5 to 1.5 million years ago. It is believed that the evolutionary tree branched at Lucy, with the australopiths eventually becoming extinct and the Homo or human ancestors continuing to evolve.
Ardipithecus ramidus (Ardi)
This hominid had large canine teeth and a chimp like skull, was bipedal but may also not have walked upright all the time, some time was spent in trees. 100 skeletons were found near Ethiopia, East Africa. "Ardi" was the female reconstruction for study.
the diversity of life
adaptation of populations of organisms to different ways of life and environments