Evolutionary Biology: Phylogenetics and Gene Families

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Questions and Answers

What distinguishes protostome development from deuterostome development?

The presence of a body cavity

Differences in cell cleavage patterns (correct)

The type of gut formed

The number of embryonic cells formed

In protostome development, how is the coelom formed?

By merging with the ectoderm

From the archenteron

By splitting of the mesoderm (correct)

Through invagination of the blastopore

What does the blastopore develop into in deuterostome animals?

The anus (correct)

The mouth

The gut

The mesoderm

Which feature is characteristic of acoelomates?

They lack a body cavity Signup and view all the answers

What processes contribute to the determination of evolutionary relationships between animal phyla?

Both genomic and morphological data Signup and view all the answers

What role do outgroups play in phylogenetic studies?

They help determine evolutionary relationships. Signup and view all the answers

Which method identifies the tree that is most likely to have produced a specific DNA set?

Maximum likelihood Signup and view all the answers

Which statement about phylogenetic bracketing is true?

It allows for predicting shared traits between two groups. Signup and view all the answers

What type of genes are formed between species as a result of speciation?

Orthologous genes Signup and view all the answers

What does the comparison of slow-changing rRNA reveal about fungi?

Fungi are more closely related to animals than to plants. Signup and view all the answers

What is the primary purpose of analyzing molecular data in phylogeny?

To uncover evolutionary relationships unseen morphologically. Signup and view all the answers

How do gene duplications contribute to gene families?

They produce homologous genes that are related. Signup and view all the answers

What differentiates paralogous genes from orthologous genes?

Paralogous genes arise from gene duplication within a species. Signup and view all the answers

What type of symbiotic relationship occurs when both species benefit from the interaction?

Mutualism Signup and view all the answers

Which of the following describes bacteria that cause human diseases?

Pathogenic bacteria Signup and view all the answers

Which toxin is secreted by bacteria as proteins and can lead to symptoms like fever and shock?

Exotoxins Signup and view all the answers

What is the process by which harmless bacteria can become harmful pathogens?

Horizontal gene transfer Signup and view all the answers

What type of bacteria are critical for the digestion of food in the human intestine?

Mutualistic bacteria Signup and view all the answers

Which of the following bacteria is known to cause typhoid fever?

Salmonella typhi Signup and view all the answers

Which of the following is a potential new class of antibiotics that may target resistant bacterial strains?

Malacidins Signup and view all the answers

Which of these bacteria is primarily utilized in biotechnological applications such as gene cloning?

Escherichia coli Signup and view all the answers

What is a key characteristic that distinguishes centipedes from millipedes?

Centipedes have one pair of legs per segment, while millipedes have two pairs. Signup and view all the answers

Which structure is responsible for locomotion in echinoderms?

Tube feet Signup and view all the answers

What type of symmetry do echinoderm larvae exhibit?

Bilateral symmetry Signup and view all the answers

Which characteristic is unique to insects within the pancrustaceans group?

Development of wings for dispersal Signup and view all the answers

How do crustaceans primarily carry out gas exchange?

Using gills Signup and view all the answers

What differentiates complete metamorphosis from incomplete metamorphosis in insects?

The presence of a pupal stage in complete metamorphosis. Signup and view all the answers

What is a common function of the modified appendages in crustaceans?

Locomotion and feeding Signup and view all the answers

What aspect of insects aids them in finding mates?

Vibrant coloration, sound, and odor Signup and view all the answers

What significant traits are associated with bilaterians?

Bilateral symmetry and complete digestive tract Signup and view all the answers

Which of the following time periods is known for the emergence of modern animal phyla during the Cambrian explosion?

Paleozoic Era Signup and view all the answers

What event is linked to the decline of Ediacaran biota?

Increased atmospheric oxygen levels Signup and view all the answers

Which characteristic is NOT typical of sponges?

Bilateral symmetry Signup and view all the answers

During which era did mammals first emerge as a diverse group occupying ecological niches?

Cenozoic Era Signup and view all the answers

Which of the following is an example of organisms categorized under radial symmetry?

Echinoderms Signup and view all the answers

What is the primary function of body plans in animals?

To organize morphological and developmental traits into a whole Signup and view all the answers

Which factor contributed to the diversification of animals during the Ordovician, Silurian, and Devonian periods?

Development of hox genes Signup and view all the answers

Study Notes

Phylogenetic Trees

Phylogenetic trees represent hypotheses about evolutionary history supported by morphological and molecular data.
Comparing outgroups and ingroups helps derive characters at specific branch points.
Maximum parsimony favors the simplest explanation with minimal evolutionary events.
Maximum likelihood identifies the tree most likely to produce a specific DNA set, based on probability.

Gene Duplications and Gene Families

Gene duplications have produced homologous gene families, clusters of related genes.
Orthologous genes form between species as a result of speciation, and their differences reflect speciation history.
Paralogous genes form within a species from gene duplication and divergence.

Prokaryotic Relationships

Prokaryotes typically form symbiotic relationships with larger organisms.
Mutualism benefits both species.
Commensalism benefits one species without affecting the other.
Parasitism benefits one species while harming the other.
Pathogens are disease-causing parasites.

Prokaryotes and Humans

Mutualistic bacteria in the gut help digest food and break down waste.
Pathogenic bacteria cause numerous human diseases.
Some pathogens are transmitted by pests.
Bacteria produce poisons classified as exotoxins (secreted proteins) and endotoxins (lipopolysaccharides).
Through horizontal gene transfer, harmless bacteria can become pathogenic through antibiotic resistance.
Antibiotic resistance is rapidly increasing due to bacterial reproduction and horizontal gene transfer.
Prokaryotes produce fermented foods like cheese, yogurt, and sourdough bread.
Prokaryotes are vital in biotechnology and genetic engineering.

Choanoflagellates and Animals

Choanoflagellates share characteristics with animals, including the presence of similar proteins like cadherin.
However, some key features like CCD domains distinguish them from animals.

The Neoproterozoic Era

Macroscopic fossils of soft-bodied multicellular eukaryotes from the Ediacaran biota (around 560 mya) are linked to animal ancestry.
Neoproterozoic rocks with microfossils exhibit the basic structure of an animal.

The Paleozoic Era

The Cambrian explosion (535-525 mya) saw the emergence of ancestors of all modern phyla.
Most Cambrian animals were bilaterians, characterized by bilateral symmetry, a complete digestive tract, and an efficient digestive system.
The Ediacaran decline is linked to new predator-prey relationships, increased atmospheric oxygen, and development of new life forms.
The Ordovician, Silurian, and Devonian periods witnessed increased animal diversity.
Cambrian animals colonized the land, diversifying into amphibians and amniotes.

The Mesozoic Era

Animal phyla from the Paleozoic continued to diversify into new habitats and traits.
Dinosaurs and mammals emerged.
Flight evolved in pterosaurs and birds.

The Cenozoic Era

Marked by mass extinctions of dinosaurs and marine reptiles.
Mammals occupied the available ecological niches.

Body Plans

A body plan refers to a set of morphological and developmental traits organized into a whole organism.
Symmetry is a key aspect of body plans, with animals possessing bilateral symmetry, radial symmetry, or no symmetry.

Protostome and Deuterostome Development

Protostome and deuterostome development differ in cleavage, coelom formation, and blastopore fate.
Protostome development involves spiral cleavage, coelom formation by splitting mesoderm, and blastopore becoming the mouth.
Deuterostome development features radial cleavage, coelom formation by budding mesoderm from the archenteron, and blastopore becoming the anus.

Diversification of Animals

The diversification of animals can be understood by examining their different clades and common characteristics.
Arthropods are characterized by a segmented body, an exoskeleton, and jointed appendages.

Myriapods

Myriapods, including centipedes and millipedes, share antennae and modified appendages.
Millipedes are herbivorous with two pairs of legs per segment.
Centipedes are carnivores with one pair of legs per segment.

Pancrustaceans

Pancrustaceans include insects and crustaceans.
Crustaceans have specialized appendages, gas exchange through a cuticle or gills, and diverse body sizes and forms
Insects are characterized by a head, thorax, and post-gential region.
Wings allowed insects to diversify and disperse.
Insects exhibit metamorphosis, with incomplete metamorphosis involving nymphs that molt into adults and complete metamorphosis involving larval stages distinct from adults.
Most insects reproduce sexually, with mate attraction mediated by coloration, sound, and odor.

Echinoderms and Chordates

Echinoderms and chordates are closely related deuterostomes.

Echinoderms

Echinoderms are slow-moving marine animals with a coelom.
They possess a water vascular system, a network of hydraulic canals with extensions called tube feet, used in locomotion and feeding.
Echinoderms exhibit bilateral symmetry in their larvae, but radial symmetry in their adults.
They encompass five major clades.

Chordates

Chordates exhibit five key characteristics at some point in their development.
These include a notochord, a dorsal hollow nerve cord, pharyngeal slits, a post-anal tail, and an endostyle..
Chordates are further divided into three subphyla:
- Tunicates
- Cephalochordates
- Vertebrates
Vertebrate innovations include a skull, a vertebral column, a well-developed brain, a closed circulatory system, and sensory organs.
Vertebrates further diversified into amphibians, amniotes (reptiles, birds, mammals), and fish.

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Description

Explore the intricate concepts of phylogenetic trees and gene duplications in this quiz. Understand the relationships between prokaryotes and the impact of mutualism, commensalism, and parasitism. Test your knowledge on evolutionary history, gene families, and species relationships.