Table of contents

1. Introduction to Biology2h 42m
2. Chemistry3h 37m
3. Water1h 26m
4. Biomolecules2h 23m
5. Cell Components2h 26m
6. The Membrane2h 31m
7. Energy and Metabolism2h 0m
8. Respiration2h 40m
9. Photosynthesis2h 49m
10. Cell Signaling59m
11. Cell Division2h 47m
12. Meiosis2h 0m
13. Mendelian Genetics4h 44m
14. DNA Synthesis2h 27m
15. Gene Expression3h 6m
16. Regulation of Expression3h 31m
17. Viruses37m
- Viruses
  37m
18. Biotechnology2h 58m
19. Genomics17m
- Genomes
  17m
20. Development1h 5m
21. Evolution3h 1m
22. Evolution of Populations3h 53m
23. Speciation1h 37m
24. History of Life on Earth2h 6m
25. Phylogeny2h 31m
26. Prokaryotes4h 59m
27. Protists1h 12m
28. Plants1h 22m
29. Fungi36m
- Fungi
  19m
- Fungi Reproduction
  17m
30. Overview of Animals34m
- Overview of Animals
  34m
31. Invertebrates1h 2m
32. Vertebrates50m
33. Plant Anatomy1h 3m
34. Vascular Plant Transport1h 2m
- Water Potential
  1h 2m
35. Soil37m
- Soil and Nutrients
  20m
- Nitrogen Fixation
  16m
36. Plant Reproduction47m
- Flowers
  33m
- Seeds
  14m
37. Plant Sensation and Response1h 9m
38. Animal Form and Function1h 19m
39. Digestive System1h 10m
- Digestion
  1h 3m
- Blood Sugar Homeostasis
  7m
40. Circulatory System1h 49m
41. Immune System1h 12m
42. Osmoregulation and Excretion50m
- Osmoregulation and Excretion
  50m
43. Endocrine System1h 4m
- Endocrine System
  1h 4m
44. Animal Reproduction1h 2m
- Animal Reproduction
  1h 2m
45. Nervous System1h 55m
- Neurons and Action Potentials
  1h 8m
- Central and Peripheral Nervous System
  46m
46. Sensory Systems46m
- Sensory System
  46m
47. Muscle Systems23m
- Musculoskeletal System
  23m
48. Ecology3h 11m
49. Animal Behavior28m
- Animal Behavior
  28m
50. Population Ecology3h 41m
51. Community Ecology2h 46m
52. Ecosystems2h 36m
53. Conservation Biology24m
- Conservation Biology
  24m

30. Overview of Animals

Overview of Animals

General Biology

30. Overview of Animals

Overview of Animals

Previous problemNext problem

1:54 minutes

Problem 7

Textbook Question

Evaluate this statement: Animals evolved from simple to complex.

Verified step by step guidance

Step 1: Understand the statement. The statement is saying that animals evolved from simple forms to more complex forms. This is a common understanding of evolution, but it's important to note that 'simple' and 'complex' are relative terms.

Step 2: Consider the evidence. The fossil record shows that the earliest life forms were much simpler than most organisms alive today. Over time, new traits and structures have evolved, leading to a greater diversity and complexity of life.

Step 3: Consider the process of evolution. Evolution is driven by natural selection, where traits that improve an organism's chances of survival and reproduction are more likely to be passed on to the next generation. Over time, this can lead to the development of new traits and greater complexity.

Step 4: Consider exceptions. While it's generally true that life has become more complex over time, this is not a hard and fast rule. Some organisms have actually become simpler over time, losing traits that they no longer need. This is known as 'regressive evolution'.

Step 5: Formulate a response. Based on the evidence and understanding of evolution, it can be said that the statement is generally true, but with some exceptions. Evolution often leads to greater complexity, but not always.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above

Video duration:

Play a video:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Evolution

Evolution is the process through which species change over time through mechanisms such as natural selection, genetic drift, and mutation. It explains how simple organisms can give rise to more complex forms through gradual adaptations to their environments. Understanding evolution is crucial for evaluating claims about the progression from simple to complex life forms.

Phylogeny

Phylogeny refers to the evolutionary history and relationships among species. It is often represented in a phylogenetic tree, which illustrates how different species are related through common ancestors. This concept helps in understanding the complexity of animal evolution and the branching patterns that lead to diverse forms of life.

Complexity in Biology

Complexity in biology often refers to the structural and functional intricacies of organisms. While some may interpret evolution as a linear progression from simple to complex, it is more accurate to view it as a branching process where complexity can arise in various forms, including multicellularity, specialization of cells, and behavioral adaptations. This understanding challenges the notion of a straightforward evolutionary ladder.

Watch next

Master Overview of Animals - 1 with a bite sized video explanation from Jason

Start learning

Related Videos

Related Practice

Textbook Question

Select True or False for each statement.

Sister chromatids are homologous chromosomes.

Non-sister chromatids are found on two different homologs.

Crossing over occurs between sister chromatids.

A chiasma forms between two of the four molecules of double-stranded DNA on duplicated homologous chromosomes.

1043

views

Textbook Question

Why is it ecologically significant that animals are heterotrophic and multicellular?

731

views

Textbook Question

Which of the following animal groups does not have tissues derived from mesoderm?

a. Annelids

b. Echinoderms

c. Cnidarians

d. Flatworms

1260

views

Textbook Question

If you followed a woman's cells through meiosis, at what stage of meiosis would the amount of DNA in one of these cells be equal to the amount of DNA in one of her G1 phase (before DNA replication) kidney cells?

865

views

Textbook Question

A species of rotifer, a small freshwater invertebrate, lost the ability to reproduce sexually millions of years ago. A remarkable feature of its life cycle is the ability to withstand dry conditions. When the rotifer's environment dries out, so does the rotifer, and it can be blown to a new area. Rotifers that land in water will rehydrate and resume an active life. A major pathogen of these rotifers is a species of fungus that cannot survive drying. Some scientists hypothesize that drying rids the rotifers of this pathogen. Design an experimental study to test this hypothesis.

837

views

Textbook Question

A species of rotifer, a small freshwater invertebrate, lost the ability to reproduce sexually millions of years ago. A remarkable feature of its life cycle is the ability to withstand dry conditions. When the rotifer's environment dries out, so does the rotifer, and it can be blown to a new area. Rotifers that land in water will rehydrate and resume an active life. A major pathogen of these rotifers is a species of fungus that cannot survive drying. Some scientists hypothesize that drying rids the rotifers of this pathogen. Why might the ability to withstand drying reduce any potential advantage of sexual reproduction in this rotifer species?

898

views

Open Question

True or false? Multicellularity is homologous in animals and land plants.

290

views

Open Question

Which of these familiar animals are all protostomes?

a. clams, shrimp, goldfish, leeches

b. butterflies, spiders, snakes, crabs

c. earthworms, snails, beetles, squid

185