chapter 16 test

artificial selection

process in which nature provides the variations and humans select the ones they find useful

natural selection

organisms best adapted to an environment survive and reproduce more than others

four steps to natural selection

overproduction, variation, competition, selection

overproduction

when a species produces more offspring that an environment can support

variation

each individual has different traits

competition

when individuals compete for limited resources; ex: food, water, space, mates

selection

the individual with the best traits will survive

does natural selection act on phenotype or genotype?

phenotype (physical appearance)

evolution

the process by which a species adapt overtime in response to changes in their environment

fossils

preserved remains or traces of ancient organisms

3 types of rocks

sedimentary, metamorphic and igneous

sedimentary rocks

formed by pieces of once-living organisms; where fossils are found

igneous rocks

forms when hot molten rock crystalizes and solidifies

metamorphic rocks

forms by extreme pressure or tempurature

pangea

a supercontinent that incorporated almost all the landmasses on earth

geological time scale

describes/tells earth’s history

law of superposition

closest layer to earth (bottom) is the oldest

embryology

the study of embryos and their development

survival of the fittest

the organisms best adjusted to their environment are most successful in surviving and reproducing

fitness

the ability to survive long enough to reproduce

adaptation

an inherited trait that increases an organism’s chance of surviving

2 types of adaption

camouflage and mimicry

camouflage

when an organism tries to blend in with their surroundings

mimicry

when an organism tries to resemble another organism

why is variation important?

the more variations within a species the more likely it will survive

descent with modification

each living species has descended, with changes, from other species over time

common descent

all living organisms are related to one another

cladogram

a diagram that shows evolutionary relationships among groups

cladistics

form of analysis that looks at features of organisms that are considered “innovations”

james hutton

proposed the idea that forces beneath earth’s surface can push rock layers upward forming mountains; concluded that earth must be older than a few thousand years

deep time (james hutton)

the idea that our planet’s history stretches back over a period of time, so long it’s difficult for the human mind to imagine

charles lyell

presented a way of thinking called uniformitarianism

uniformitarianism

the idea that geological processes we see today must be the same ones that shaped earth millions of years ago

lyell and hutton also relied on there being enough time in earth’s history for the changes to take place

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lamarck hypothesis

proposed the idea that all organisms have the urge to become more complex and perfect; also believed organisms could change the size (and shape) of their organs by using their bodies in new ways

^NOT TRUE (idk if we need to know or not; in slideshow)

jean-baptiste lamarck

one of the first naturalist to suggest species aren’t fixed; recognized there is a link between an organism’s environment and it’s body structure

thomas malthus

reasoned that if the human population grew unchecked, there wouldn’t be enough space or resources for everyone

darwin realized that malthus’ reasoning applied to other organisms also; ex: more offspring die being reaching maturity

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charles darwin

naturalist: an expert of natural history

what theory did darwin come up with?

developed the scientific theory of evolution that explains how modern organisms developed over long periods of time

what was darwin’s job on the beagle?

to collect and observe specimens of plants, animals, rocks and fossils wherever they went

what 3 patterns did darwin observe?

1. species vary globally
2. species vary locally
3. species vary overtime

galapagos island

where the most important observations were made; not only did the islands differ in many ways, the plants and animals did also

how long was the voyage?

5 years

evidence of evolution

fossil record, homologous body structures, analogous structures, vestigial structures, embryology, biochemical evidence

fossil record

fossils: a record of the history of life on earth; provide a record of species that lived long ago; helps show similarities with modern species

be prepared to draw a cladogram

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homologous body structures

similar anatomy in different types of animals because of a common ancestor

analogous structures

same function however not structured the same way

vestigial structures

"leftover traces of evolution that serve no purpose; ex: our appendix (helpful long ago but not anymore)

embryology (evidence of evolution)

embryos of all vertebrates are very similar early on

biochemical evidence

DNA with more similar sequences suggest species are more closely related