Please enable JavaScript.
Coggle requires JavaScript to display documents.
evolution (speciation (species= a population of similar organisms that can…
evolution
speciation
species= a population of similar organisms that can interbreed to produce viable, fertile offspring
-
-
-
microevolution=small scale, single population
macroevolution= grand scale, across species
-
molecular evidence
-
-
-
-
...can all be compared to determine relativeness of organisms (EX: we can lean about the evolution of humans and our closest living relative, the chimpanzee, by comparing chromosomes
mutation
-
-
-
can be beneficial, neutral, or harmful, for the organism, but mutations do not "try" to supply what the organism "needs"
the only mutations that matter to large- scale evolution are those that can be passed on to offspring (occur in reproductive cells like eggs and sperm and are called germ line mutations)
intro to evolution
-
population- group of individuals of the same species that live in the same area and reproduce with one another
-
-
mechanisms
-
genetic drift
-
unlike natural selection, an advantageous trait is not necessarily being selected for
mutation
-
random (beneficial, harmful, or neutral)
natural selection
occurs because there is variation, heredity, and the environment cannot sustain unlimited population growth
-
-
migration/gene flow
-
movement of individuals, and their genetic material, from on population to another (EX: pollen being blown to a new destination, people moving o new cities or countries)
if gene versions are carried to a population where those gene versions previously did not exist, gene flow can be a very important source of genetic variation
sex can introduce new gene combinations into a population and is an important source of genetic variation
natural selection
-
-
carrying capacity (differential reproduction= not all individuals get to reproduce to their full potential
when the above 3 criteria are met, evolution by natural selection will is occurring
sexual selection
-
-
sexual selection is often powerful enough to produce features that are harmful to the individuals survival
EX: extravagant and colorful tail feathers or fins are likely to attract predators as well as interested members of the opposite sex (peacock tails, birds of paradise, and elephant seals fighting for territory)
fossil evidence
-
-
radioactive dating
radioactive elements in fossils or sediments surrounding fossils (EX: radioactive carbon to nitrogen in 60,000 years)
-
artificial selection
-
-
EX: produce, pets, and livestock
co- evolution
-
-
EX: predator/ prey & parasite/ host, competitive species, mutualistic species
micro-evolution
-
occurs over short periods of time, like from one generation to the next
-
homologous vs. analogous
homologous
characters in different organisms that are similar because they were inherited from a common ancestor that also had that character
common ancestry/decent- when one species is the ancestor of two or more species later in time (EX: forelimbs of tetrepods, humans, whales, birds, etc.)
analogous
have seperate evolutionary origins, but are superficially similar because they have both experienced natural selection that shaped them in a similar way
converent evoloution- process in which two distinct lineages evolve a similar characteristic independently of one another (EX: flight in birds vs. flight in birds)
-
-