Diversity and Evolution Flashcards
What are the Titles under the Hierarchal Classification system that we use to classify organisms?
Kingdom Phylum Class Order Family Genus Species
An organism’s two part name, is constructed of two of the Classification titles, which ones?
The Genus & Species
The Genus is capitalised, the Species lower case - both are italicised
What are six categories of facts for Evidence of Evolution?
Morphological Comparative Homologous Features Analogous Features Vestigial Features Embryological Evidence
Morphological Evidence In being evidence for Evolution
Having to do with shape & structure
Can be found in the fossil record
Identify features in fossilised
(Mineralised) parts of organisms or
Mummified tissues
Can look for transitional forms
Intermediates between ancestral &
derived speciesComparative Anatomy being evidence for Evolution
It’s the search for similar or distinguishing features features among living organisms
Number of similarities tells us
roughly how closely related some
organisms are
Homologous Features being evidence for Evolution
Features that have similar underlying structure as a result of shared ancestry… but the features may serve different functions now - these feature do not need to look the same
Analogous Features being evidence for Evolution
Features look similar, or may just perform a similar function, but have different ancestral origins (evolved independently)
Eg. Wings of Bats, Birds, & insects
Cause by Convergent Evolution
Different organisms face the same
challenge, so they develop similar
solutions
Vestigial Features being evidence for Evolution
A trait that was useful in the ancestor that now serves no function… or maybe a different function
Ex. Appendix (Used to be Caecum)
The pelvic girdle in whales
Claws in pythons or boas
Embryological evidence for Evolution
Embryology is the study of development of fertilisation to “birth”
We all start as a Zygote, which is then carries out cell division, to create an Embryo (we all start off looking the same)
Ex. Gills, tails
Biogeography being evidence for Evolution
Pattern of organism distribution that tells us something about their evolutionary history
Fossil Records being evidence for Evolution
Evidence of Extinction
Fossilized remains of transitional forms
Molecular Evidence for Evolution
All organisms have DNA
What does Molecular Evidence provide?
Support for Common Ancestry & provides a source of variation, Mutations
What are Mutations?
Copying errors that happen in DNA Replication during the formation of new cells/asexual reproduction
They are the only source of variation in asexually reproducing organisms
They occur at a regular rate, so by comparing DNA or amino acid sequences we can tell how closely related different species are, and when they’re diverged
What is Phylogenetics?
The study of evolutionary relationships
The relationships are represented with trees
What do nodes represent on a Phylogenetic tree?
A shared common ancestor
The closer the node = more closely related
What is the Gradualism theory?
Evolution is slow
Accumulation of small changes
Many transitional forms
What is the Punctuated Equilibrium theory?
Gould’s hypothesis
Evolution can be fast
Long periods without changes then bursts of new species
Gradualism and Punctuated Equilibrium is a what?
Spectrum
What are the number of Amino Acid differences in Human to Tuna sequences?
21
What are the number of Amino Acid differences in Human to Bullfrogs?
19
What are the number of Amino Acid differences in Human to Snapping Turtle?
14
What are the number of Amino Acid differences in Human to Kangaroo?
10
What are the number of Amino Acid differences in Human to Rhesus Monkey?
1
What makes a species/organism/genre successful?
An individuals’ (& species) ability to persist in the environment is decided by reproductive success
What is a species defined by?
The ability of its member’s to interbreed
What is Biotic Potential?
A measure of an individuals’ success and ability to contribute
What four factors effect Biotic Potential?
Birth Potential: # Of babies per birth
Breeding Frequency: How often they have babies
Length of Reproductive Life: From sexual maturity to “death or sterility”
Capacity for Survival: Likelihood the babies live
What is Speciation?
The formation of a new species
What is required for Speciation?
Selective pressures operating on a group of organisms
Pressure causes a divergence in strategy
Organisms become better adapted to particular conditions
Shape/Structure genetics
Groups can no longer interbreed
Reproductive Isolation
What are the two types of Speciation?
Allopatric Speciation
Simpatric Speciation
What is Allopatric Speciation?
Geographic isolation of groups
Each new group can experience different selective pressures (or mutations) & eventually are reproductively
isolated even if they are reintroduced
What is Simpatric Speciation?
No geographic isolation
Spontaneous genetic change
Specialization to niches within an environment
What is Artifcial Selection?
When humans (not the environment or nature) select which traits are desirable
May not be naturally advantageous
Domesticated Animals
Designer Breeds
Crops (agricultural)Sexual Selection
Female (usually) get to select for traits they find attractive
What factors affect sexual selection?
Sexual Dimorphism
The sexes of a species look different - if a am,e can afford to look pretty, he’s healthy
Good Genes
Agree with Natural Selection
Parasites - female s will select against
They want good-looking kids (sons)
Modern examples of Evolution
Antibiotic Resistance
Covid lineage/Variants
