Evolution of the Brain Flashcards
(22 cards)
Define evolution
the gradual change of a species
Explain the theory of evolution by natural selection and the roles of Darwin and Wallace on developing the theory
Darwin and Wallace proposed evolution by natural selection, a theory that says evolution proceeds by differential success in reproduction. Darwin traveled South American and the Galapagos finding evidence in turtles and finches. Wallace got the idea while suffering fever, and focused study on importance of biogeography.
Explain the 4 main observations on which Darwin based his hypothesis.
- Reproduction will increase a population rapidly unless factors limit it
- individuals of a species arent identical
- some variation is inherited
- not all offspring survive to reproduce
Describe how variations, adaptations and sexual selections work together in the theory of evolution according to Darwin
Darwin inferred that variations affect the probability that they will survive and reproduce, and adaptations increase likelihood of offspring through sexual selection which is when each sex has anatomical and behavioral features that favor reproductive success.
Define convergent evolution
shows similarities in behavior or structure among unrelated animals due to adaptations to similar environments
Define homoplasy
resemblance between features due to convergent evolution
Define homology
similarity based on common ancestry
Define analogy
refers to similar function, a human hand and elephant truck have similar function even though they look different
Define mutations
spontaneous changes in genes, a rapid form of evolution
Define chromosomes
found in nucleus, carries genetic information
Explain the basic concept of species classification
each species has 2 names
explain what phylogeny and taxonomy are
phylogeny-evolutionary history of particular group of organisms-represented as family tree
taxonomy-the classification of organisms
six reasons to study other species
outstanding features like sensory skills, convenience, comparison, preservation, economic importance, and treatment of disease
explain the role of learning during evolution
ability to learn is an important adaptation in order to find food and avoid danger
explain the brain and neural similarities between mammals
All mammals have similar types of neurons. Same basic structures and general patterns are shared among all mammals and they evolved from common ancestors, but the relative size and location are different
describe the two methods used to study evolution of the brain
endocast (uses skull to make cast of brain) and living animals (allows for study of internal structure of brain)
explain what the encephalization factor is
measure of brain size relative to body size
explain the main factors on human brain evolution, such as the change of volume of specific areas, which areas evolved larger and the consequences of these enlarged areas in the stages of development
brain has become larger and cortex became enlarged to modern size by brain regions developing later, resulting in long gestation periods
briefly describe the relationship between brain size evolution and traits (bipedalism, tools, teeth, etc.)
as brain and cortex size grew, the ability to use tools decreased and necessity for large jaws and teeth decreased
cost and benefits of having large brains
benefits: increased survival and ability for group interaction
costs: long gestation period, prolonged dependence on parents, high metabolic cost, and more susceptible to mutation
explain the role of the genes on having a large brain
a few crucial genes can have a great effect on development, and small changes in DNA can alter timing and location of gene expression
explain the differences in skin color, facial features and stature of the human species
in response to climate conditions
