List of unsolved problems in biology

This article lists currently unsolved problems in biology.

Problems

Alkaloids	The function of these substances in living organisms which produce them is not known[1]
Arthropod head problem	A long-standing zoological dispute concerning the segmental composition of the heads of the various arthropod groups, and how they are evolutionarily related to each other.
Basking shark	Only the right ovary in this fish appears to function, the reason is unknown.
Biological aging	There are a number of hypotheses why senescence occurs including those that it is programmed by gene expression changes and that it is the accumulative damage of biological processes.
Blue whale	There is not much data on the sexuality of the biggest animal ever.[2]
Botany/plants	What is the exact evolutionary history of flowers, called Darwin's abominable mystery?
Butterfly migration	How do the descendants of Monarch butterfly all over Canada and the US eventually, after migrating for several generations, manage to return to a few relatively small overwintering spots?
Cambrian explosion	What is the cause of the apparent rapid diversification of multicellular animal life around the beginning of the Cambrian, resulting in the emergence of almost all modern animal phyla?
Cell size	How do cells determine what size to grow to before dividing?
Cognition and decisions	How and where does the brain evaluate reward value and effort (cost) to modulate behavior? How does previous experience alter perception and behavior? What are the genetic and environmental contributions to brain function?
Computational neuroscience	How important is the precise timing of action potentials for information processing in the neocortex? Is there a canonical computation performed by cortical columns? How is information in the brain processed by the collective dynamics of large neuronal circuits? What level of simplification is suitable for a description of information processing in the brain? What is the neural code?
Computational theory of mind	What are the limits of understanding thinking as a form of computing?
Consciousness	What is the brain basis of subjective experience, cognition, wakefulness, alertness, arousal, and attention? Is there a "hard problem of consciousness"? If so, how is it solved? What, if any, is the function of consciousness?[3][4]
Diseases	What are the neural bases (causes) of mental diseases like psychotic disorders (e.g. mania, schizophrenia), Parkinson's disease, Alzheimer's disease, or addiction? Is it possible to recover loss of sensory or motor function?
Evolution of sex	What selective advantages drove the development of sexual reproduction, and how did it develop?[5]
Extraterrestrial life	Might life which does not originate from planet Earth also have developed on other planets? Might this life be intelligent?
Free will	Particularly the neuroscience of free will
Gall wasp	It is largely unknown how these insects induce gall formation in plants; chemical, mechanical, and viral triggers have been discussed.
General anesthetic	How do these theories work?
Glycogen body	The function of this structure is not known.
Golgi apparatus	In cell theory, what is the exact transport mechanism by which proteins travel through the Golgi apparatus?
Hammerhead shark	The reason for their distinctive and unusual head structure is not known.
Homing (biology)	A satisfactory explanation for the neurobiological mechanisms that allow homing, has yet to be found.
Korarchaeota	Their metabolic processes are so far unclear.
Language	How is it implemented neurally? What is the basis of semantic meaning?
Latitudinal diversity gradient	Why does biodiversity increase when going from the poles towards the equator?
Learning and memory	Where do our memories get stored and how are they retrieved again? How can learning be improved? What is the difference between explicit and implicit memories? What molecule is responsible for synaptic tagging
Loricifera	There are at least 100 species of this phylum that are yet to be described, but none of them is known to be present in the fossil record.
Movement	How can we move so controllably, even though the motor nerve impulses seem haphazard and unpredictable?[6]
Development and evolution	How and why did the brain evolve? What are the molecular determinants of individual brain development?
Neural computation	What are all the different types of neuron and what do they do in the human brain?
Neuroplasticity	How plastic is the mature brain?
Noogenesis - the emergence and evolution of intelligence	What are the laws and mechanisms - of new idea emergence (insight, creativity synthesis, intuition, decision-making, eureka); development (evolution) of an individual mind in the ontogenesis, etc.?
Origin of life	Exactly how and when did life on Earth originate? Which, if any, of the many hypotheses is correct?
Paradox of the plankton	The high diversity of phytoplankton seems to violate the competitive exclusion principle.
Perception	How does the brain transfer sensory information into coherent, private percepts? What are the rules by which perception is organized? What are the features/objects that constitute our perceptual experience of internal and external events? How are the senses integrated? What is the relationship between subjective experience and the physical world?
Sleep	What is the biological function of sleep? Why do we dream? What are the underlying brain mechanisms? What is its relation to anesthesia?

See also

• List of unsolved problems in neuroscience

References

1. Aniszewski, p. 142
2. Articleworld.org Blue Whale
3. Sejnowski, Terrence J.; Hemmen, J. L. van (2006). 23 problems in systems neuroscience (PDF). Oxford [Oxfordshire]: Oxford University Press. ISBN 0-19-514822-3.
4. Tononi, G; Koch, C. (2015). "Consciousness: Here, there and everywhere?" (PDF). Philosophical Transactions of the Royal Society London B.
5. Thomas N. Sherratt, David M. Wilkinson. Big questions in ecology and evolution. Oxford University Press US, 2009. ISBN 978-0-19-954861-3
6. University of Copenhagen (24 January 2007). "Thinking With The Spinal Cord?". ScienceDaily. Retrieved 25 May 2016.