Lecture 1.1 and 1.2

Evolution

inherited changes in the properties of groups of organisms over time

descent with modification

Darwin’s phrase for evolution: species share common ancestry and change across generations.

Gradualism

Evolutionary change occurs in small steps over long time.

Differences between even radically different organisms had evolved by small steps (Darwin)

population change

Evolution occurs at the population level, not the individual.

Evolution occurs by changes in frequencies of different variant within a population (Darwin)

Lamarck

Life has many origins (spontaneous generation); each lineage becomes more complex over time, result resembles chain of being. Extinction does not occur

Who????

Lamarck

Whose hypothesis is this?

Darwin

Life represented as a tree with one origin; different lineages arise by speciating (splitting); lineages diverge, but do not necessarily become more complex. lineages can go extinct

Who????

Darwin

Whose hypothesis is this?

Variation

Differences among individuals in a population.

inheritance

Passing of traits from parents to offspring (genetic).

adaptation

A trait that increases an organism’s fitness (survival and reproduction)

natural selection

Process where individuals with advantageous traits leave more offspring.

genetic drift

Random changes in allele frequencies, often in small populations.

gene flow

Movement of alleles between populations.

mutation

Random change in DNA sequence; source of new variation.

common descent

 All species trace back to shared ancestors.

scala naturae

“Great Chain of Being,” pre-Darwinian view of life arranged in a hierarchy.

lamarckism

Hypothesis that acquired traits (e.g., long giraffe neck from stretching) are inherited.

orthogenesis

Theory that evolution follows a predetermined straight-line path.

mutationism

Early idea that new species arise directly from mutations, without selection.

modern synthesis

Integration of Darwin’s natural selection with Mendelian genetics (1930s–40s).

genetic

“inherited changes” means that the changes are —

voyage of the beagle

a pivotal scientific expedition aboard HMS Beagle that profoundly shaped Charles Darwin’s ideas about evolution.

Charted coastlines (especially South America) and collect natural history observations

inductive

• Darwin collected a huge body of empirical data (plants, animals, fossils, geological notes) during the Voyage of the Beagle and later studies.

• From these particular observations, he built a general theory of evolution by natural selection.

This is using — reasoning

inductive reasoning

Patterns we see in nature leads us to general principles

slowly

Darwin believed that change happened (fast/slowly)

Alfred Russel Wallace

independently came up with the idea of evolution by natural selection and catalyzed darwin to publish

unchanging

The great chain of being thought of species as —

imperfection

The great chain of being described variation as —

essentialism

Every entity has an “essence” (set of unchanging characteristics) that defines what it is.

means that each species has a fixed, perfect “type”

industrial melanism

the evolutionary process where darker-colored individuals in a species become more common than lighter ones because of industrial pollution.

 

blending inheritance

an early (but incorrect) idea about heredity

• The idea that offspring are a “blend” or average of their parents’ traits.

• Example: A tall parent × a short parent → medium-height child.

neolamarckism

modified version of lamarc’s theory of evolution

use and disuse, but also adds heredity ideas

orthogenesis

Organisms evolve in a fixed direction, often toward increasing complexity. (incorrect)

raw material

Mutation is the — for natural selection 

microevolution

Small-scale evolutionary changes within a population or species over a short period of time.

microevolution

(micro/macro evolution) focuses on changes in allele frequencies due to factors like natural selection, mutation, gene flow, and genetic drift

macroevolution

Large-scale evolutionary changes that occur above the species level, often leading to the formation of new species, genera, or higher taxa.

microevolution

— is observed in real time

macroevolution

— is observed in fossil record or long-term studies

No

Does natural selection always act for the good of the species?

differential reproductive success

Natural selection operates solely by —

 Last Universal Common Ancestor (LUCA)

the most recent population of organisms from which all life on Earth today descends. It’s not the very first life form, but rather the common ancestor of bacteria, archaea, and eukaryotes.

no

Are viruses living?

grow, reproduce, evolve

Viruses —, —, and —

metabolic processes

Viruses dont carry out —

systematics

the study of patterns of diversity of organisms and the relationships among them

classification

allocation of things to groups, according to shared characteristics or perceived or deduced affinities

taxonomy

theory and practice of classification, particularly of organisms

taxonomy, nomenclature, classification

systematics includes —, — and —

nomenclature

a system of names and the rules for their formation and use

phylogeny

the history of descent of a group of taxa from their common ancestors

monera, protista, fungi, plantae, animalia

the 5 kingdom system included which 5 kingdoms?

bacteria, archaea, eukarya

the 3 domain system includes

root

the common ancestor of all taxa in a tree

internal node

branchpoint in a tree

terminal node

endpoint in a tree

clade

a group of 2 or more taxa that includes both their common ancestor and all their descendants

lineage

A temporal series connected by ancestor-descendant relationships

2n - 1

for a phlogeny with n terminal nodes:

taxa =

n-1

for a phlogeny with n terminal nodes:

clades =

n

for a phlogeny with n terminal nodes:

lineages =

monophyletic

Clades are — groups

monophyletic

A — group contains a common ancestor and ALL of its descendants

paraphyletic

a group that contains a common ancestor and some, but not all, of its descendants

polyphyletic

a group that consists of members of more than one lineage, but does not include the most recent common ancestor of those lineages and all of its descendants

monophyletic

this is a — group

paraphyletic

this is a — group

polyphyletic

this is a — group