BIOL 3030 Exam 1 Bernal

Evolution

change in characteristics of a population through time

Anaximander (610-546 BC)

proposed that the sun, moon, and stars were physical objects, not deities

Aristotle (384-322 BC)

Presented logic and hypothesis testing.

Catastrophism

sudden events would change geological features and presence of species at a given time. Also thought the Earth was fairly young.

Xenophanes (570-470 BC)

questioned the date of the earth when he found marine fossils at the top of a mountain.

James Hutton

formally suggested the earth must be very old based on observations of sediment layer which he attributed to erosion, pressure, sedimentation, etc.

Charles Lyell

Wrote Principles of Geology; proposed uniformitariansim

Uniformitarianism

Geological features we see today are gradually changing through time; processes that cause change are happening today

Naturalism

explaining the world based on observable phenomena

Mundus Subterraneaus

Book that gave recipe for creating worms and flies by leaving out rotten food.

Empedocles

Proposed that all living things are made up of independent body parts that were running around alone and mixed together to make organisms. Only functional combinations persisted.

Francesco Reddi

Proved that life could not spawn from nonliving material

Scala Naturae

All species created in their perfect, unchanging form by a deity, as a link in a chain from most simple (worms) to complex (human).

Al jahiz

Ethiopian thinker, Wrote "Book of Animals" in 700s-800s , hinted at natural selection

George Louis Leclerq

Wrote Histoire Naturelle, said "Common morphological characteristics are an expression of close relationships between them."

Erasmus Darwin

Wrote Zoonomia: All life has evolved through a "single living filament", changing through time.

Wrote Temple of Nature: Noted struggle for existence

Inheritance of Acquired Characteristics

an organism's efforts during it's lifetime cause changes to it's phenotype, and these changes are passed to offspring

Lamarck

French guy who believed in IAC

Patrick Matthew

Proposed a similar idea to natural selection in the boat building book he wrote.

Charles Darwin

observed reason for atolls, credited with developing natural selection

Published Origin of Species

Alfred Wallace

Naturalist that studied in the Malyan archipelago

Observations gave rise to biogeography

Found that flora and fauna of Asia and Australia were distinct despite being close together.

Ali Wallace

Malayan assistant of Alfred Wallace

Origin of Species

Book by Darwin that covered:

Natural Selection

Artificial Selection

Evidence for Evolution

Artificial Selection

Humans choose which individuals to mate, to obtain desirable characteristics

Natural Selection

Differential survival

Differences in reproductive success.

Darwin's 2 main ideas

natural selection

Organisms have common descent

Variation in the population and a selective agent

Natural selection requires 2 components:

Thomas Malthus

Principles of Population: Human populations grow faster than the available food, so there would be overpopulation if it wasn't for war, famine, disease

Darwin borrowed heavily from this work

transformational, variational

Lamarck's process is ________, Darwin's process is _________

A hammer, a sifter

An example of a transformational process would be getting fine dust with __________, while variational is like using __________

Descent with modification

Darwin's other main idea:

- species split from common ancestor and slowly gain differences

- This is why closely related species are similar

Lamarck

_________ would claim that all species who acquired hair evolved independently.

Darwin

_________ would claim that all species are related by descent and it is possible to have similar structures/adaptations as the common ancestor

- How to account for complex structures with a slow process?

- Vestigial traits

- Why would variation persist?

- How are traits inherited?

Four key problem with Origin of Species

Adaptation

inherited trait that makes an organism more fit in its environment, as a result of natural selection

Can

Environment _____ cause phenotypic variation

genotype, phenotypes

The same _____ may produce different ________ under different environmental conditions

Norm of Reaction

both environment and genetics can play a big role in the phenotype

Life History

refers to how organisms invest their energy in reproduction over their lifetimes

Antagonistic pleiotropy

a trait that increases fitness in one condition can decrease fitness in another setting

structures to detect light

Eyes originated as ________ and progressively became more complex

Vestigial Traits

Traits that were useful in ancestors that are inherited today, but that have lost their original use.

Exaptation

a heritable trait that increases fitness in a certain environment that was originally selected for a different function but also advantageous

(ex. feathers)

Physical Constraints

Why can't elephants have long legs?

Why can't owls have 360 vision?

Nature of the Environment

NS problem: It is impossible to be a 'perfect' organism if the target is always moving

Abiotic environments always changing allowing for different species to thrive over time

Evolutionary Arms race

evolutionary forces that lead to the development of defenses on the host, and mechanisms to evade such defenses on pathogen/predator

Lack of Foresight

NS problem: Natural selection is not predictive, and it is unable to forecast the future. Selection can only happen on past and present events.

Carl Linnaeus

In his book: Systema Naturae, tried to classify all known species

Developed binomial nomenclature (father of taxonomy)

Ernst Haeckel

coined the term phylogeny;

famous idea was "embryology recapitulates phylogeny" which suggests that embryonic stages of organisms are represented in their ancestors

Phylogeny

branching relationships of species, as they give rise to descendant groups over time

Characters

any observable or measurable characteristic of an organism

Traits

represents the specific state of the character

Taxon

groups represented at tip of phylogeny

Nodes

sections where branches of phylogeny split. Represents common ancestor. Not alive today

Root

represents the common ancestor to all groups in the tree. base of the tree

Hypotheses

Phylogenies represent _________ about evolutionary history, and such they can be tested, challenged, and refuted.

Polytomy

more than one branch coming out of one node

Monophyletic group

a common ancestor and all of its descendants

Clade

group of species that share a single common ancestor

Polyphyletic Group

when a group does not include common ancestor of all members, nor all descendants from that ancestor

Paraphyletic group

contains the group's common ancestor, but not all descendants

Rooted tree

ancestor from which all other lineages derive is included in the tree

Unrooted tree

tree not designed from the perspective of a single common ancestor

Cladogram

no branch lengths, just relationships

Phylogram

branch lengths indicating some sort of evolutionary change

Chronograms

trees that provide information about the time of split between different groups

Taxonomy

area of biology that is associated with describing, classifying, identifying and naming organisms

Systematics

the field associated with the classification of organisms based on their similarities, and their evolutionary history

Analogy

similarity in function or position between organs that have DIFFERENT evolutionary origin

Homology

Structures that have same evolutionary origin, even if they have a different function

Synapomorphy

shared derived characteristic (homology);

defines clade

Homoplasy

represents a trait that is similar between two species, but these two species do not share a common ancestor (analogy)

Symplesiomorphy

shared primitive characteristic that is not present or different in one of the species in the group

Maximum Parsimony

Among competing hypotheses, the tree with the fewest number of changes should be selected

Disadvantage of Maximum Parsimony

based on the same information, you can end up with multiple trees that show different relationships

Distance Based Methods

Phylogenies based on the pairwise distances between species or populations

Limitations of distance based methods

Group species according to similarity regardless of true evolutionary history

Likelihood based methods

evaluates different trees and determines their likelihood or probability based on a chosen evolutionary model

Bootstrap Resampling

"sampling with replacement"

Can be used for all methods

Does not represent the probability of the whole tree, but rather the confidence in branching events