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22 Cards in this Set

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  • Back
Chimpanzees live in family groups with male-kin societies where females are forced to leave the group once reaching adulthood, a social structure known as a ____society.
Humans and chimpanzees have genomes of nearly the same size and share DNA sequences similarity of _____%.
The earlist fossils with human-like features date back to ____ million years ago.
The discovery of Lucy, a fossil nearly 4 million years old, showed the first time at which human-like ancestors walked upright, a type of locomotion known as_____.
The most widely accepted hypothesis for the evolution of dipedalism is the _____ hypothesis.
Research has shown that at least ____ different human species evolved and then went extinct.
The first human species to leave Africa was Homo _____
As a result of an ice age 500,000 years ago, the population of humans in the North (Europe) evolved into the _____.
As a result of an ice age 500,000 years ago, the population of humans in the South (Africa) evolved into _____.
Homo sapiens
Due to a drought in Africa 120,000 years ago, the entire Homo sapien population was reduced to less than _____ individuals
The phenomenon is which an entire population is the descendants of only a few individuals is known as a genetic _____.
The discovery of the human genetic bottleneck was made by studying human _____ DNA.
Every modern human evolved from a small group of Homo sapiens that originated on the continent of _____.
When comparing the genomes of any two humans from any part of the world, their DNA sequences are _____ % identical.
The hypothesis that suggests that modern Homo sapiens left Africa and out competed all other human species to extinction is the _____ Model.
Out of Africa or Replacement.
The hypothesis that local population evolved into humans and subsequent interbreeding with African migrants led to the genetic homogeneity of modern humans is known as the _____ model.
Regional Continuity or Multi-Regional Evolution.
Describe the complex patrilocal society of the common chimpanzee.
Chimpanzee society is very male dominated. All of the males in a family group are related because males remain with the same family group as adults. They have a strong kinship with one another. Females, however, do not remain with the family group they were born into. At adulthood they must leave that family group and find another to join. This type of society is biologically advantageous in that it prevents inbreeding.
How does chimpanzee tool usage demonstrate the existence of chimpanzee culture?
While all chimpanzee groups use simple tools, such as sticks to retrieve termites and stones to crack nuts, how they used them to do these things varies between family groups. This shows that tool usage is a learned technique passed on from adult to young, an example of a cultural aspect of their society.
How did the ice age of 500,000 years ago and the resulting drought in Africa ultimately result in the evolution of Homo sapiens?
There were two groups of human ancestors ( Homo heidelbergensis), one living in Europe and the other in Africa at the time of an ice age 500,000 years ago, that were seperated by the resulting drought. The two groups evolved along different lines, with the European gropu becoming neanderthals, while the group in Africa evolved on a different pathway and eventally became Homo sapiens.
What is a genetic bottleneck and how do we konw that one occurred to the Homo sapien population?
A genetic bottleneck is a phenomenon where for some reason, possible environmental change, a group of organisms is forced nearly to extinction. The very small population size results in inbreeding. This inbreeding then results in a decrease in the genetic diversity of the surviving population. By studying mitochondrial DNA, we now know that the human population was at one point decreased to less than 10,000 individuals.
Explain 2 theories for why Homo sapiens are the only remaining human species and tell which one is the more likely of the 2 and why?
The replacement model or out of Africa model states that when Homo sapiens evolved and left Africa, they spread out into the territory of other human species and out competed them for the available resources. The other human species could no longer find enough food to survive and thus became extinct, leaving only Homo sapiens. The other theory, known as the Regional continuity model or multi-regional evolution model state that homo sapiens spread out from Africa and interbred with the other existing species so thoroughly that eventually there was only one human species. The replacement or out of Africa model is the favored theory because a very high similarity of genome sequences between all existing humans suggests that there wasn't significant interbreeding and that we all came from one species, the homo sapiens that drove the other human species to extinction.
When comparing the genomes of any two humans from any part of the world, their DNA sequences are ___% identical.