Biology: Chapter 22

before darwin what was the belief at the time called?

historical special creation

historical special creation belief

species were

a. created independently at the same time

b. do not change through time

c. created recently 10,000 years ago

historical special creation belief mechanism

supernatural force

what were the people that were before darwin

aristotle

carolus linnaeus

curvier

aristotle

species differ on “scale of nature”, but do not change, created by God

carolus linnaeus

classified species, which were created by God

Cuvier

fossil studies

Fossils

remains or traces of organisms from the past

before darwin observations suggested

1) species change over time

2) extinctions

3) time-series of species apperance

4) environments had changed over time

Jean-Baptiste de Lamarck believed in

 independent progression

independent progression’s mechanism

inheritance of acquired traits

adaptation from inheritance of acquired traits

organisms constantly change

develop traits that them succeed in their environment

offspring inherit traits developed by their parents

Lamarck believed what caused evolution

species evolve through use and disuse of body parts

acquired traits are inheritable

innate drive causes evolution

were lamarck’s idea supported by evidence?

no

independent progression

species arise when individuals develop altered traits in response to their habits

evolve independently, in parallel to other species

problems with Lamarck’s mechanism?

clusters of similiarities

patterns of similarities suggest organisms are related

what was darwin’s key contribution to evolutionary biology?

the theory of evolution by natural selection

evolution by natural selection

• evolved from one or few species (descent with modification)

• are related; some share a more recent common ancestor than others

• arise over long periods of times as a result of the gradual accumulation of small changed across generations

explain darwin’s tree of natural selection

lots of branching pattern of relatedness

descent with modification

why was darwin’s contribution considered the parent of modern evolutionary theory

1) Provided EVIDENCE that evolution had occurred

2) Proposed NATURAL SELECTION mechanism of evolution, could explain ADAPTATION

3) Provided EVIDENCE that evolution would occur by natural selection

darwin

natural selection caused evolution

darwin: natural selection causes evolution

Adaptation occurs though natural selection

• New species evolve if environment changes or organisms  

  migrate to new environment.

• Adaptation to variety of environment → diversity of life

• All species are from a common ancestor. (unity in life)

Scientific theory

A well-supported explanation of an aspect of the natural world, based on a body of facts repeatedly confirmed through observation and experiment. Supported by a vast body of evidence

Comparison of Darwin’s and Lamarck’s theories

• Darwin and Lamarck both agreed that species evolve,

  characters are inheritable

• Lamarck: acquired characters inheritable

• Darwin: member difference exits even without use/disuse.

(inherited, basis of natural selection)

- Evolution caused by natural selection

Vestigial structures

homologous structures that have lost some or all their original function in a species through evolution.

Analogy

similarity between two species that is due to convergent revolution rather than to decent from a common ancestor

Convergent evolution

independent evolution of similar features in different lineages (a group of species related by descent from a common ancestor)