Human Evolution

▪️Human proof of evolution: Analyze the diagram and list 4 changes to the human skull which have taken place throughout the evolutionary process.

3.9 - 3 million years ago Australopithecus afarensis —— had ape like faces —— small face (slightly flat on one side) —— square like jaw 3 - 2 million years ago Australopithecus africanus —— head became rounder (slightly larger brain) —— skull became larger —— larger jaw —— square like jaw 2.5 - 1.5 million years ago Homo habilis —— skull more similar to human skull —— skull became smaller —— smaller jaw 1.8 million - 300,000 years ago Homo erectus —— head is more elongated —— jaw is very sharp + rectangular —— skull became larger

What is human evolution?

A scientific theory of the origin of species of plants and animals.

Finally: Human evolution (CULTURALLY!)

Although humans will probably not evolve further physically, our culture will always continue to evolve and change throughout time.

▪️ What makes us human?: How do they contribute to the field of Anthro?

Anthropologists have examined evidence from millions of years to develop a theory of the evolution of humanity. This study of evolution required centuries of examinations that was built upon the research of many various scientists. Basically = allows us to further understand the theory of evolution.

When did primates and humans diverge?

At some point, scientists estimate that between 5 - 8 million years ago, this common species diverged Into 2 distinct lineages. One of which were the hominids, or humanlike species, and the other which ultimately evolved into the African great ape species living today (chimpanzees, etc) unknown ancestor / \ hominids apes

Which animal is the most closely related to humans?

DNA comparisons indicate that chimpanzees are humans' closest living relatives. Likewise, analyses of human DNA suggest that all modern humans are descendants of people who lived in Africa between 100,000 and 150,000 years ago.

What other proofs exist to support evolution?

Gregor Mendel discovered that when two plants of different colours were crossbred, the resulting flowers were either one colour or the other. — heredity factors do not blend, but keep their individuality. — mendel's work indicates that humans inherit a variety of characteristics from their biological parents, yet they still maintain their own unique DNA code — over many generations, certain traits could be passed down or altered.

▪️Genetic proof of evolution: What did Mendel discover about human genetics while studying plants?

He discovered that we inherited a variety of characteristics from our biological parents but still maintained a unique DNA code. He also discovered that sometimes, certain genes can skip a generation or several generations. For example, a woman can have red hair, and this trait may only be passed to her grandchildren, skipping her own children (skipping a generation)

Natural Variance

Humans are made up of complex DNA structures. We have evolved so that no two genetic codes are the same (except identical twins). Each have variances. If an external factor were to happen that could eliminate humans, our variances would allow some to survive and some to become extinct. This is why 2 people with similar DNA codes (family) should not sexually reproduce because the result would be a child with deformities. Not viewing the family as a potential mate provides our species with a much better chance of survival.

Will humans continue to evolve?

Humans are unlikely to evolve into a new, separate species because no human group is truly isolated anymore, given our transportation systems. Without genetic isolation there is no further opportunity for speciation among humans.

Are primates and humans similar? Explain.

Humans did not evolve from present day apes. Rather, humans and apes share a common ancestor that gave rise to both. This common ancestor, although not identical to modern day apes, was almost certainly more apelike than human-like in appearance and behaviour.

▪️Genetic proof of evolution: How does his discovery impact the beliefs surrounding the evolution of humans?

If Mendel's heredity theory is correct, that would explain how our ancestors evolved from primitive humanoids to a more sophisticated species. We have basically been built upon the traits of our ancestors.

Adaption:

If organisms belonging to the same species lived in two different areas, they will change over time according to environmental conditions and resources.

Define natural selection (Charles Darwin)

In 1832, Charles Darwin, undertook a five year study while traveling the world. He devised his theory of « natural selection » while researching the different finches in the Galapagos Islands.

Examples of Migration Patterns

Mass Extinctions (Ice Age, Asteroid collision) offered surviving species an opportunity, as regions that were once inhabited became vacant and environments changed. Surviving populations adapted to newly vacated habitats and available resources, each group following its own evolutionary path and diversifying into new distinct species.

Natural selection

Natural selection is a natural mechanism by which the fittest member of a species survive to pass on their genetic information, while the weakest are eliminated (die off) because they are unable to compete in the wild. Natural selection is often termed as "survival of the fittest" and other times "elimination of the weakest"

▪️Physical proof of evolution: What fundamental beliefs did the discovery of the stones contradict?

Religious leaders and other scientists that required more evidence to support such a theory would oppose the discovery of the stones. - went against writings of the Bible and creationism -fossil evidence was believed to be "sketchy" because it didn't have step by step / stages of evolution -could not comprehend that species evolved and transformed into different species

Will our human brain continue to evolve?

The human brain may have reached e edge of its computational limit. The constraint on a bigger brain is directly linked to the implications it would have for the women who are carrying the offspring.

▪️Physical proof of evolution: What is the importance of the stones found in Somme River?

The stones discovered along Sommes River in France we're not shaped naturally; appeared to have been molded or shaped into tools/weapons. These stones indicated that humanity hand once been capable of producing primitive tools.

What role do primitive tools have in mapping out our evolution?

Tools were made of stone, bone, and antler. As humans progressed through the ages, the more specialized these tools became. These tools support the theory of evolution because they indicate that as the intricacy of tools increase, humans are advancing through the evolutionary process.

Migration patterns

When environments change, or when species colonize new environments, evolution can occur very rapidly.

Significance of natural selection

Without natural selection, evolution would not occur, and not all organisms would adapt to their environment. Natural selection ensures the best of the best pass on their genes and survive, to create an overall stronger and more adapted species.

▪️ What makes us human?: What are the 3 methods used in anthropology to study human evolution?

a) paleonthology = the study of fossil evidence b) arghaeology = the study of cultural remains c) DNA analysis = the study of DNA & the biological evolution at the molecular level

Example of adaption

— Darwin's Finches It was noted during his research in the Galápagos Islands that Finches, who originally strayed from South America, developed differently depending on which island they lived on. Food recourses varied, therefore, the Finches who had characteristics high best suited their environment survived and reproduced (their beaks adapted differently depending on what they ate, e.g insect, seeds, leaves, etc)

Overall evolutionary process

— skull grows larger in time — nose increases (protrudes) w/ a higher sense of smell — brow edges decreased — brain grows larger