Evolution Exam Review

Evolutionary thinking emerged in the ___ century in ___

19th century, Europe

it was not until ___ and ___ independently described natural selection as the major basis of biological evolution that the field of evolutionary science was firmly established.

charles darwin and alfred russel wallace

biological evolution occurs when:

specific processes cause the genomes of organisms to differ from those of their ancestors

what is the idea behind the scala naturae?

the entire natural world arranged as a single continuum as a hierarchical ladder of all matter and life as decreed by God

what is the idea behind natural theology?

each organism has been specially created by god, because species would never change or become extinct, new species would never arise

natural theologists wanted to name and catalog all creations, and merged ___ and ___

aristotle’s scala naturae and the great chain of being

great chain of being

nature’s hierarchy illustrated as a series of steps (stone, flame, plant, animal, man, heaven, angel, god). this provided a fixed hierarchy of life, but wasn’t very useful for classifying life’s diversity at a finer scale

branch of biology that classifies organisms

taxonomy

Carl LInnaeus

organized all living things known at that time into a genus, family or order.

he believed that all plants and animals had been created by god and could therefore be placed into natural groups that revealed god’s devine plan

father of modern philosophy, also made an important connection between geometry and algebra

Descartes

contributed to physics, astronomy, cosmology, mathematics, and philosophy. considered the father of modern science

Galilei

created theory of universal gravity

newton

created heliocentric model

copernicus

established the importance of observation, experimentation, and inductive reasoning (scientific method)

Francis Bacon

branch of biology that studies the world distribution of plants and animals

biogeography

what ideas from biogeography contributed to the idea of evolution?

similar looking animals occupy similar habitats in geographically separated regions

what is comparative morphology?

comparison of the anatomical structures of organisms.

what findings from comparative morphology contributed to the idea of evolution?

similarities of body plans, body tissues, or homologous traits between different animals

vestigial organs

coccyx, vermiform appendix, and wisdom teeth are all

vestigial organs

study of fossils

paleobiology

what observations from paleobiology contributed to the study of evolution?

stratification (horizontal layering) of sedimentary rocks

similarities between fossils in similar areas

the concepts of catastrophism and gradualism

what concept came from the idea that each layer of fossils represented creatures that had died in a local catastrophe such as floods?

catastrophism

gradualism

slow continuous physical processes, acting over long periods of time, produced earth’s geological features. variations come about gradually in nature over time as opposed to a sudden catastrophic event

uniformitarianism

the geological processes that sculpted earth’s surface over long periods of time are exactly the same as the processes that are observed today

first naturalist to offer a detailed theory of evolution

Lamarck

could be described by the thought that life was driven inexorably from simplicity to complexity, that humans and other large species descended from microbes

Lamarckism

Lamarck thought that a ___ caused organisms to become better suited to their environments

metaphysical perfecting principle

what were the two mechanisms that fostered evolution, according to Lamarck?

principle of use and disuse - body parts grow in proportion to how much they are used (ex. giraffe neck)

inheritance of acquired characteristics - changes that an organism acquires during its lifetime are inherited by its offspring

what were the failures of Lamarck’s theories?

most body structures do not respond in the way that he predicted

structural changes acquired during an organism’s lifetime are not inherited by the next generation

he also couldnt explain how this might happen, though he discussed a “natural tendency toward perfection”

In 1831, Darwin joined on a voyage around the world on the navy ship called __

HMS Beagle (istg if this is an exam question)

natural selection favors ___ traits, which are defined as ___

adaptive traits, defined as genetically based characteristics that make an organism more competent and able to survive and reproduce

by favoring ___, natural selection allows species to change and diverge through evolutionary time scale (evolutionary divergence)

individuals that are well adapted to the environments in which they live

the evolutionary alteration and diversification of ancestral species can also be called

descent with modification

modern synthesis focuses on

the gradual processes of evolutionary change within populations

modern synthesis considered ___ as the primary mechanism of evolution

natural selection

large-scale evolutionary changes in a species

macroevolution

small-scale genetic changes in populations in response to a specific shift in environmental circumstances

microevolution

gradual accumulation of microevolutionary changes results in…

macroevolution

does natural selection create variation or new genetic traits?

no, it selects for genes already present in populations

new genetic strains are added to the population through ___

mutation and horizontal gene transfer

how did snakes lose their limbs?

expression of Hoxc6 at the base of the neck in a chick embryo causes limb buds to generate and forelimbs to generate. in pythons, both Hoxc6 and Hoxc8 are expressed. the expression of these two genes suppresses the development of limb buds and instead produces limbs there.

Mutations in the ZRS are responsible for the loss of hindlimbs in snakes

What is ZRS?

zones of polarizing activity regulatory sequence. know that it is an enhancer for the expression of sonic hedgehog gene and triggers the growth of limbs all the way to an animal’s toe.

how did the woolly mammoth survive in the cold? (well until they went extinct 💀 )

1600 affected genes code for proteins involved in cold adaptation. a variant TRPV3 gene found in the mammoth contributed to long fur, large fat reserves, and general tolerance to cold.

evolution is the core theory of modern biology because…

its explanatory power touches on every aspect of the living world

what is orthogenesis? why is this not the commonly accepted theory?

the idea, derived from the scala naturae, that evolution produces new species with the goal of improvement.

it is not accurate because we know that evolution proceeds as an ongoing process of dynamic adjustment, not toward any fixed goal. natural selection preserves the genes of organisms that function well in particular environments, but cannot predict future environmental change.