BOT3015 - Evolution and Human Influence

1785 - James Hutton

Founded uniformitarianism, predicted gradual change, and believed forces today = forces in the past

1912 - Alfred Wegener

formulated the first theory suspecting a Continental drift, conducted that Pangea broke up 200 mya., and concluded a matching fossil record

Plate Tectonics

A theory stating that the earth's surface is broken into plates that move. This helped prove Wegener's theory of the Continental Drift.

Inner Core

Most inner part of the Earth. Solid due to high pressure.

Outer Core

Just above the inner core. It is molten Iron

Mantle

This is below the crust and above the outer core of the Earth. It is mostly solid rock of iron and

magnesium-silicate - flows slowly.

Crust

The outermost layer of the Earth's structure. It is mostly granite (continents) and basalt (oceans).

Lithosphere

The crust + upper mantle. It is broken into ~20 plates that can move over plastic mantle.

Fossil Records - Significance

Matching fossils records support idea of Pangea (a single large continent)

Araucaria

One of many plant genera distributed solely in the Southern

hemisphere (Argentina, Africa, and Australia). This plant supports the idea of distribution of plates.q

Earth Age

4.5 billion years old (Ga).

Stromatolites

Earliest microfossils from 3.5 Ga.

Cyanobacteria

Earliest evidence 2.7-2.1 Ga (disputed fossils)

Embryophytes

Appear in mid-Ordovician (470 Mya)

Embryo

(a zygote protected by female gametophyte) and is essential for survival on land

Haploid Gametophyte

Makes gametes

Diploid Sporophyte

Makes spores

Sporopollenin and Cuticle

Dessication-resistant compounds

Vascular Plants

Appeared in the late Silurian/early Devonian (~420 Mya)

Seed Plants

First appeared during Devonian Era(~380 Mya)

Heterospory

Seed plants that produce two kinds of spores.

Megaspores

Heterospory spore that is retained by sporophyte (protects embryo)

Microspores

Heterospory spore that travels to fertilize megaspore

Domestication Syndrome

Caused by selection by humans that leads to plants not being able to adapt in the wild. Consequences include: loss of dormancy, synchronous flowering, change in abscission, larger grain/fruit size, and even loss of reproductive ability, etc

Domesticated Plants

Dependent on people for their survival

Cultivated Plants

Not dependent on people for survival

Landraces

A locally adapted domesticated variety of an agricultural crop native to a particular area; Mutation and hybridization gave rise to diverse varieties

Nikolai Vavilov

One of first to note lower resilience of domesticated plants compared to wild relatives. Proposed interbreeding! This scientist collected germplasm (seeds, tubers,

etc) of all domesticated crops and wild relatives (~2500 species) This scientists observations led to discovering 8 centers of origin

China

Center of Origin for rice, soybeans, & peach

Indo-Malay

Center of Origin for banana & coconut

Indo Burma

Center of Origin for Mango & eggplant

Central Asia

Center of Origin for lentils & apples

Fertile Crescent

Center of Origin for oats, wheats, & dates

Mediterraneon

Center of Origin for olives, cabbages, & mint

Ethiopia

Center of Origin for coffee, okra, & seseame

Mesoamerica

Center of Origin for corn, chocolate, & tomato

Andes

Center of Origin for potato, lima beans, & corn

Chile

Center of Origin for strawberries & some potaoes

Chaco-Pantanal

Center of Origin for cashew, rubber, & pineapple

Population

A group of freely interbreeding individuals of the same species in the same habitat

Wide-Spread Species

Species that might have thousands of populations.

They vary in environmental conditions and can become isolated!

Narrow Endemics Species

Species that might have only one or a few populations

Annual Life Span

completes its life cycle (seed to seed)

within 1 year or less

Biennial Life Span

Tends to live for 2 years. First year

grows roots and leaves. Second year, long

stems and flowers. Dies after setting seed.

Perennial Life Span

Lives several years and (usually) flowers several times. Can be woody orsurvive underground (e.g. tubers)

Semelparous

Reproduces only once in its lifetime: includes annuals, biennials and some perennials (e.g. Yucca whiplei). They spend ~25% of their stored energy into a massive reproductive even

Iteroparous

Reproduces many times during its life: includes most perennial plants. Spends 5-15% of their energy in each

event. Non-reproductive juvenile stage

Hermaphroditism

Flowers with both male and female gametes

Monoecious

Plants with both male and female flowers

Dioecious

Plants with either male or female flowers

r-Selection

Type of selection with many offspring and little investment

K-Selection

Type of selection with little offspring and huge investment

Macroenvironment

The larger scale of abiotic and biotic conditions a population may experience such as elevation, latitude, temperature, rainfall, etc.

Microenvironment

The small-scale set of abiotic (non-living) and biotic (living) conditions that an individual plant experiences.