Quiz 1 Intro, Tree of Life, History of Life

A  Meteorites wiped out some taxa on some continents but not on others.

B  Biogeography, i.e. the distribution of taxa on planet earth can be entirely explained by temperature patterns. That is why global warming is predicted to help many animals spread further than today.

C  Continents moving and thus joining or separating have created or interrupted land bridges for animals to use for migrations. Also sealevel rise and glaciers affected distribution.

A  They are all Amniotes which means that, unlike amphibians, they produce a terrestrially adapted egg, which means that the embryos of amniotes were provided with their own aquatic environment. The embryo in amniotes is is protected by amniotic membranes.

B  They are all poikilotherms, able to control their body temperature. That is how they survived through periods of changing climate.

C  They are the first taxa to not lay eggs. Amphibians were the last taxon to still lay eggs among tetrapods, and today only birds still have that ability.

A  Plants conquered land early before there were animal predators, and what we see today is actually the least diversity of plant life the planet has seen.

B  Plants could only really dominate land after asteroids hit earth and wiped out dinosaurs that were grazing on plants.

C  The ancestral green algae developed into mosses that were less well adatped to dry conditions. A cuticle and vascular systems in tracheophytes and dispersal strategies (multicellular gametangia, and multicellular embryos) as found especially in flowering plants (Angiosperms), allowed plants to create the dominant forms we see today.

A  The cambrian explosion could not happen before the continents merged and formed the supercontinent Pangea.

B  Photosynthetic algae produced oxygen and increased the oxygen content on the planet, which was necessary for animal life to develop.

C  An asteroid hit earth at that time (hence the name explosion), and wiped out land predators (Dinosaurs), so that marine invertebrates could develop freely and conquer land.

A  Prokaryotes evolved from Eukaryotes by abandoning vestigial features.

B  Proto-Eukaryotes lacking mitochondira engulfed mitchondria (which were individual cells) and through endosymbiosis became the Eukaryotes we know today.

C  Eukaryotes are more complex and evolved from prokaryotes by developing mitochondria themselves.

A  Yes, if two animals look the same or similar, then they either are the same species or closely related.

B  Not necessarily, because envitonmental factors can select the evolution of similar features in different taxa through convergent evolution. For example dolphins are closely related to hippopotamuses and other mammals, but they superficially look more like sharks.

C  Yes, dolphins and sharks would not have the same shape, unless they share almost identical DNA.

A  Natural selection expresses the success in survival and reproduction of better adapted individuals among a population (where genetic variation causes differences within the population). It is crucial to understand why some traits are inherited and other traits (or entire species) do not continue in a lineage.

B  “Natural selection” is another word for mass “extinction” that occours when meteroites or asteroids hit planet earth. Then many species go extinct.

C  Natural selection explains how evolution unfolds according to an intentional pre-arranged plan.

A  Even a single mutation of one gene location can lead to a dramatical evolutionary saltation, creating for eaxmple a new species.

B  Mutations are not naturally occurring without radioactive polution, and play a minor role in natural evolution. Usually mutations lead to death and no positive outcome.

C  The differences between even radically different organisms have evolved by small steps through intermediate forms, not by leaps.

A  Darwin was the first to argue that species had diverged from common ancestors and that species could be portrayed as one great family tree representing actual ancestry.

B  Darwin argued that individual Giraffes get longer necks during their lifetime by trying to stretch, and then pass that aquired feature on to their offspring.

C  Darwin argued that finches arrived at the Galapagos islands by boat, and lst the ability to fly (like penguins), so they never left Galapagos again.

A  Changes through time in individual organisms, such as those that transpire in embryonic development (ontogeny).

B  Change in the heritable characteristics of biological populations over successive generations.

C  Change of abilities in an indivual person or animal through consistent training.