Ch20n : development of evolutionary thinking Flashcards
biological evolution
the process by which some individuals in a population experience changes in their DNA and pass those modified instructions to their offsprings
natural history
the branch of biology that examines the form and variety of organisms in their natural environments
natural theology
a belief that knowledge of god may be acquired through the study of natural phenomena
taxonomy
the science of the classification of organisms into an ordered system that indicates natural relationships
biogeography
the study of the geographical distributions of plants and animals
morphology
the form/shape of an organism
vestigial structures + 2 ex
an anatomical feature of living organisms that no longer retain its ancestral function e.g. our coccyx or the fact that pigs have 2 toes that never touch the ground
fossil
the remain/traces of an organism of a past geologic age embedded and preserved in Earth’s crust
paleobiology
the study of ancient organisms
catastrophism
the theory that Earth has been affected by sudden, violent events that were sometimes worldwide in scope
gradualism
the view that Earth and its living systems changed slowly over its history
uniformitarianism
the concept that the geological processes that sculpted Earth’s surface over long period of times- such as volcanic eruptions, earthquakes, erosion, and the formation and movement of glaciers- are exactly the same as the processes observed today
artificial selection
selective breeding of organisms to ensure that certain favorable/desirable traits appear at higher frequencies in successive generations
natural selection
the evolutionary process by which alleles that increase the likelihood of survival and the reproductive output of the individual that carry them become more common in subsequent generations
adaptive trait
a genetically based characteristic preserved by natural selection, that increases an organism’s likelihood of survival and its reproductive output
evolutionary divergence
a process whereby natural selection or genetic drift causes populations to become more different over time
descent with modification
biological evolution
population genetics
the branch of science that studies the prevalence and variation in genes among populations of individuals
modern synthesis
a unified theory of evolution developed in the middle of the 20th century
microevolution
small-scale genetic changes within populations often in response to shifting environmental circumstances or chance events
macroevolution
large scale evolutionary patterns in the history of life, producing major changes in species and higher taxonomic groups
biological lineage
an evolutionary sequence of ancestral organisms and their descendants
historical biogeography
t study of the geographical distributions of plants and animals in relation to their evolutionary history
comparative morphology
analysis of the structure of living and extinct organisms
homologous traits
characteristics that are similar in 2 species because they inherited the genetic basis of the trait from a common ancestor
orthogenesis
an obsolete theory that evolution is goal orientated, striving towards perfect organism
Aristotle’s ladderlike classification of nature (scala naturae) from simplest to most complex
- minerals(least complex)
- plants
- animals
- humans
- gods
biblical account of creation in 3 parts
- organisms were created by god
- species didn’t change over time or become extinct
- new species could never arise
linnaeus is the creator of ….
taxonomy
3 reasons that contradict natural theology
- biogeography:
why did some species have limited geographical distributions where as others were wide spread? especially if they were all created in the Garden of Eden - comparative morphology:
- Buffon: why did vestigial structures exist
- if limbs were specially created for different means of locomotion, why didnt the creator use entirely different structures and materials - Fossils:
relatively simple fossils in lower strata and more complex higher
theory of catastrophism (Cuvier) in 2 parts
proposed …
- abrupt changes in strata = dramatic shifts in ancient environments
- fossils = remains of organisms that died in a local catastrophe
Lamark theorized 2 mechanisms that fostered evolutionary change
- principle of use and disuse
e. g body parts grow in proportion to how much they are used - principle that inheritance of acquired characteristics
e. g. long legged wadding birds descended from short legged ancestors that stretched their legs to stay dry
rejection of Lamark’s 2 principle
- use and disuse : most structures did not respond in the way he suggested
- principle that inheritance of acquired characteristics: structural changes acquired during an organism’s lifetime are not inherited by off spring
4 contributions to the development of evolutionary worldview that Lamark made
- all species change over time
- new characteristics are passed from one generation to the next
- organisms change in response to their environments
- hypothesized the existence of mechanisms that fostered evolution
Hutton’s gradualism theory contradicted what theory…
Cuvier’s catastrophism
what were the 2 hypothesis that Darwin proposed ?
- The struggle for existence: individuals within a population compete for limited resources .
- selective breeding and heredity was a form of artificial selection:
hereditary characteristics may allow some individuals to survive longer and reproduce more than others
3 observations that lead the hypothesis: The struggle for existence
- most organisms produced more than one/ two offspring
- populations do not increase in size indefinitely (permanently)
- food and other resources are limited for most populations
2 observations that led to the hypothesis: selective breeding and heredity was a form of artificial selection
- individuals within populations exhibit variability in many characteristics (size form, color behavior)
- many variations appear to be inherited by subsequent generations
Darwin’s prediction
a population’s characteristics will change over the generations as advantageous, heritable characteristics become more common
In Darwin’s theory of descent with modification he proposed that natural selection…
is the mechanism that drives evolutionary change by preserving advantageous traits and eliminating disadvantageous ones
the shape of the beaks of Darwin’s finches, industrial melanism (pepper moth) and changes in horse teeth are all examples of …
natural selection
4 characteristics distinguish Darwin’s theory from earlier explanations of biological diversity and adaptive traits
I don’t know if this is important
- he provided purely physical explanations rather than spiritual
- he recognized evolutionary change occurs in groups of organisms, rather than individuals: some members of the group survive and reproduce more successfully than others
- he described evolution as a multistage process: variations arise within groups, natural selection eliminates unsuccessful ones and generations inherit successful variations.
- like Lamark he understood evolution occurs because some organisms function better than others in a particular environment
what are the 2 levels of evolutionary change
- microevolution
2. macroevolution
4 pieces of evidence for evolutionary change with examples
- adaptation by natural selection
- development of pesticide resistance in insects or antibiotic resistance in bacterial infections - fossil record
e. g. non-flying dinosaurs linked to modern birds because fossils allow for biological lineages to be observed - historical biogeography
e. g. monkeys in America have many different features than African monkeys - comparative morphology
e. g. mammoth is 98% similar to the African elephant
