Evolution of Animals II

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Questions and Answers

What primary adaptation allows Dipnoi (lungfish) to survive in dry environments?

Ability to crawl using their long pectoral fins (correct)

Functional gills for underwater breathing

Resistance to predation through camouflage

High metabolic rate to outlast dry spells

Which feature distinguishes tetrapods from other vertebrates?

Presence of dorsal fins

Four limbs with digits (correct)

Solid vertebral column

Ability to breathe using gills

Which of these factors contributed to the colonization of land by vertebrates?

Increased moisture availability

Escape from aquatic predators

Decrease in competition in aquatic habitats

Availability of food resources like insects (correct)

What is the significance of the fossil Tiktaalik in the study of vertebrate evolution?

It possesses characteristics of both fish and tetrapods. Signup and view all the answers

What defines the 'double life' of amphibians?

Their metamorphosis from aquatic to terrestrial forms Signup and view all the answers

Which feature is NOT characteristic of mammals?

Absence of teeth Signup and view all the answers

What adaptation allows primates to have enhanced grasping ability?

Opposable thumb Signup and view all the answers

Which statement is true about human and chimpanzee chromosomes?

Two ancestral chromosomes fused to form chromosome 2 in humans Signup and view all the answers

Which of the following features is shared by all hominins?

Bipedal locomotion Signup and view all the answers

What does 'binocular vision' enable?

Depth perception Signup and view all the answers

What is a significant evolutionary trait of the first representatives of the Homo genus?

Manufacture of complex tools Signup and view all the answers

Which characteristic is NOT associated with Archaeopteryx?

Small gonads Signup and view all the answers

Which trait distinguishes primates regarding their social behavior?

Parental care and social behaviors Signup and view all the answers

What was the estimated time period for the first hominins?

6.5 million years ago Signup and view all the answers

Which characteristic is NOT typical of mammals?

Absence of limbs Signup and view all the answers

What is one key characteristic that defines invertebrates?

Absence of a backbone Signup and view all the answers

How do invertebrate organisms primarily get classified?

Based on embryological or anatomical characteristics Signup and view all the answers

Which statement correctly describes the significance of the notochord in vertebrate evolution?

It provides structural support and eventually develops into the vertebral column Signup and view all the answers

What proportion of all known animal species do invertebrates constitute?

Around 95% Signup and view all the answers

Which of the following innovations is associated with the early tetrapods' ability to colonize land?

Modification of limbs for locomotion on land Signup and view all the answers

What is an example of an exaptation in vertebrate evolution?

Lungs originally used for buoyancy becoming functional for breathing Signup and view all the answers

Which characteristic is NOT used in the classification of tetrapods?

Habitat type Signup and view all the answers

What role do gill arches play in vertebrate evolution?

They evolved into the jaw structure in later vertebrates Signup and view all the answers

Study Notes

Dipnoi (Lungfish) Adaptations

Dipnoi, commonly known as lungfish, possess lungs as a primary adaptation for surviving in dry environments. This allows them to breathe air when water sources are scarce.

Tetrapod Distinguishing Feature

The presence of four limbs, or tetrapod limbs, sets tetrapods apart from other vertebrates. This adaptation facilitated movement on land.

Factors Contributing to Vertebrate Colonization of Land

The development of lungs for air breathing was crucial for survival in terrestrial environments.
The evolution of limbs enabled vertebrates to move and explore land effectively.
The emergence of strong, supportive skeletons provided structural support for terrestrial locomotion.

The Significance of Tiktaalik

Tiktaalik, a transitional fossil discovered in 2006, provides vital insights into the evolution of tetrapods. Its unique skeletal structure demonstrates how early vertebrates transitioned from aquatic to terrestrial life.

Double Life of Amphibians

Amphibians are known for their "double life," as they live part of their lives in water and part on land. They require water for reproduction and typically spend their larval stages in aquatic environments.

Feature NOT Characteristic of Mammals

Laying eggs is not characteristic of mammals. Mammals give birth to live young.

Enhanced Grasping Ability in Primates

Primates possess opposable thumbs, enabling them to grip objects with great dexterity. This adaptation enhances their grasping abilities.

Human and Chimpanzee Chromosomes

Human and chimpanzee chromosomes share a high degree of similarity, indicating a close evolutionary relationship. However, the human karyotype has 46 chromosomes, while chimpanzees have 48. This difference is attributed to a fusion event in the human lineage.

Shared Feature of Hominins

All hominins, including humans, share the defining feature of bipedalism, the ability to walk upright on two legs.

Binocular Vision

Binocular vision, the ability to see with both eyes simultaneously, provides enhanced depth perception and spatial awareness. This advantage is crucial for navigating and interacting with the environment.

Evolutionary Trait of Early Homo

An increased brain size and a more complex brain structure are significant evolutionary traits observed in the earliest representatives of the genus Homo.

Characteristic NOT Associated with Archaeopteryx

Archaeopteryx, a transitional fossil between dinosaurs and birds, possessed many bird-like features, but it did not have a beak. Instead, it had sharp teeth.

Primates are characterized by their complex social structures and intricate social interactions. This behavior is often linked to the evolution of large brains and a high level of intelligence.

Estimated Time Period for First Hominins

The first hominins are estimated to have appeared around 6-7 million years ago.

Characteristic NOT Typical of Mammals

Being cold-blooded is not typical of mammals. Mammals are warm-blooded, meaning they can regulate their body temperature internally.

Key Characteristic of Invertebrates

Invertebrates are defined by the absence of a vertebral column, or backbone.

Classification of Invertebrates

Invertebrate organisms are primarily classified based on their anatomical structures, body plans, and physiological traits.

The Significance of the Notochord

The notochord is a flexible rod that provides structural support in early vertebrate embryos. Its evolutionary significance lies in its contribution to the development of the vertebral column, a key feature defining vertebrates.

Proportion of Invertebrates in Known Species

Invertebrates constitute an estimated 95% of all known animal species, emphasizing their vast diversity and ecological importance.

Innovations Associated with Early Tetrapod Colonization

The modification of gill arches into jaws allowed for effective predation and food acquisition on land. The development of limbs with digits enabled locomotion and exploration in terrestrial environments.

Example of an Exaptation in Vertebrate Evolution

The evolution of feathers in birds is considered an exaptation. Feathers evolved from scales in their reptilian ancestors, initially serving a different purpose, but later adapted for flight.

Characteristic NOT Used in Tetrapod Classification

The presence or absence of a notochord is not used in the classification of tetrapods. All tetrapods possess a vertebral column, replacing the notochord during development.

Role of Gill Arches in Vertebrate Evolution

Gill arches, initially serving as respiratory structures in fish, underwent evolutionary modification. They contributed to the formation of jaws and other supporting structures in the head, significantly influencing the development of vertebrates.

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Description

This quiz covers the key characteristics and classification of invertebrates and vertebrates. It focuses on the evolution of body symmetry, innovations among vertebrates and tetrapods, and the significance of embryological features. Test your understanding of phylogenetic relationships and adaptations that enabled vertebrates to thrive on land.