Biology-unit 8 (evolution)

imprints or remains of organisms found in rock

fossils

The complete disappearance of a species from the Earth

extinction

believed in uniformitarianism (the idea that earth has slowly and steadily transformed overtime by a series of tiny changes) and that earth is very old

Charles Lyell

believed in the inheritance of acquired traits (animals adopted to the environment by their muscles and organs changing overtime due to their use or disuse)

Lamarck

Who wrote the essay On Population which argued that human populations grow faster than the resources they depend on. When populations become too large, famine and disease breakout, this case populations, and check by killing off the weakest members

Malthus

A naturalist who had a copy of Charles Lyell’s book on geology with him as he traveled to South America on a ship

Darwin

Where species rapidly divers into new forms, occurs when the organisms encounter a new or changed ecosystem

adaptive radiation

humans choose the puppies with the most desirable traits to breed again to have more puppies of the same traits(also applies to plants)

artificial selection

Traits favorable for a species surviving and reproducing the world we selected for fecundity (the ability to produce many offspring)

natural selection

Reproductive success(must have survival, mating success, and family size)

fitness

A feature that is common in a population because it provides some improved function, produced by natural selection

adaptation

is the ultimate force of all new alleles, are random, and favorable ones accumulate in the population

role of mutations

Every modern organism are descendants of these

common ancestor

hypothesis: a proposed explanation for a phenomenon made as a starting point for further investigation. theory: a well substantiated explanation acquired through the scientific method and repeatedly testing and confirmed through observation and experimentation. Scientific law: a statement based on repeated experimental observations that describes some phenomenon of nature not why it happens.

hypothesis vs theory vs law

composed of physical remains of species

fossil record

exhibit traits common, to both an ancestral group and its descendants

transitional fossil

Specific anatomical parts that show variations on a common design

homologous structures

Similar traits that are found in species not closely related

analogous structures

Shrunk and remnants of structures that were more useful in the ancestral form of a species

Vestigial structures

Embryologist have found many similarities in the unborn/unhatched or embryo stage of animals

developmental

The study of the geographic distribution of species

biogeography

Hypothesis of endocytosis proposes that mitochondria and chloroplasts were formally small prokaryotes that began living within larger cells

Cellular

Sequences of DNA and chromosomes or sequences of amino acids and proteins that are identical or nearly identical

molecular

macroevolution: where entire species change, go extinct, or diverge into new species. Microevolution: mechanism that causes changes with the frequencies of alleles within a population.

macroevolution versus microevolution

psychological stress, predation, competition and sexual selection

Factors that promote natural selection

Inappropriate levels of a critical environment environmental factor

physiological stress

when one organism is hunted and killed by another

predation

The result of other organisms attempting to use the same resources

competition

occurs when the female(usually) response to specific behaviors or physical traits

sexual selection

when the right level of an environmental factor is present, population levels will be growing or after their peak, this is the optimal range for that factor

how physiological stress promotes natural selection

Presence of predators will encourage the selection of individuals with traits to defend against or evade those predators

how predation promotes natural selection

Both interspecific and interest specific competition will ensure that weaker, “ less fit” individuals survive and reproduce less often

how competition promotes natural selection

for mating (ex. The female peacock picks the male peacock with the brightest, most colorful, and largest tail)

how sexual selection promotes natural selection

Stabilizing selection, directional selection, and disruptive selection

what is natural selection can alter variation in a population

Favors intermediate phenotypes, acting against, occurs in stable environment

stabilizing selection

Acts against individuals at one of the phenotypic extremes, during environmental change or when a population migrate to a new habitat

directional selection

Favors individuals at both extremes of the phenotypic range, occurs in patchy environments

disruptive selection

Natural selection, genetic drift, and gene flow

factors that can alter alle frequencies

A change in the gene pool of a population due to chance, especially in small populations

genetic drift

Bottleneck effect, when a population suddenly reduces in size because of a random event (like a natural disaster or disease)

example of genetic drift

The movement of individuals(migration) or gametes/spores between populations and can alter allele frequencies in a population

gene flow

Emergence of a new species

speciation

A species is a population or group of populations whose members have the potential to interbreed and produce fertile offspring

biological species concept

Classifies organisms based on observable phenotypic traits (forms), choice of trait can be subjective

morphological species concept

Species or groups or populations that share the exact same ecological niche

ecological species concept

Offspring of two different species, they are usually sterile (infertile), sometimes happens when species are closely related

hybrid

Often, two species get physically separated, long enough that they evolve separately until they are separate species

formation of new species

Gradualism: evolution happens slowly and continuously, small changes that add up over a long period of time (gradual change), a smooth, steady change. Punctuated equilibrium: evolution happens in short, rapid bursts, long periods of little to no change, the change happens when a small population becomes isolated or the environment changes quickly

gradualism vs punctuated equilibrium

The evolutionary history of a species or group of species

Phylogeny

uses shared derived characters to group organisms into clades, including an ancestral species and all it’s descendants

cladistics