A clown fish uses his fins to fan water across a glistening mass of eggs, keeping them aerated. A silver arowana scoops up his fertilized eggs with his mouth and holds them gently for two months, until a host of miniature adults swims free from his jaws. A seahorse drifts through coral, his belly pouch swollen with unborn young.
Most fish are uninvolved parents. They dump their eggs and sperm, then swim off and let nature take its course. But some species of fish take their parental duties more seriously and among them, the majority of caring parents are dads. Care from mothers, or from both parents at once, is much less common. In a study published last fall in Evolution, researchers found evidence that paternal care, the system in which dads are the sole caretakers, has evolved dozens of times in fish.
These fish arent exactly helicopter dads. Their most common parenting style is simply guarding eggs after theyre fertilized. Some people are surprised this is considered care, said Frieda Benun Sutton, an evolutionary biologist at the City University of New York.
But it does count. To learn more about why this type of care in fish usually comes from dads, Dr. Benun Sutton and her co-author, Anthony Wilson, of Brooklyn College, took a deep dive into the family history of fish parents. They started with an evolutionary tree, built by other researchers in 2017 using genetic data, that shows how almost 2,000 fish species are related. Then they mapped onto the tree all the information they could find about parental care in those species: Were young cared for by fathers, mothers, both or nobody? They also added other factors including the size and number of each fishs eggs and how theyre fertilized.
The completed tree showed that care by fathers is no evolutionary accident: It has arisen at least 30 separate times. Hundreds of the species in this sample have absent mothers and caring fathers. But why?
We do see consistent patterns that occur across the entire evolutionary tree, Dr. Benun Sutton said.
One important pattern is that every species with paternal care also uses external fertilization sperm and egg meeting out in the open and spawns in pairs, not groups. This makes sense, the authors say, because when fertilization happens in a group or inside a females body, a male cant be sure of his paternity. Caring for those young could be a waste of his energy, evolutionarily speaking. But if he fertilizes a fresh batch of eggs and then stands guard over them, he believes hes caring for fish that share his genes.
The link between external fertilization and doting dads is a hypothesis several decades old. But more recent research has shown that external fertilization doesnt ensure fish dads end up caring for their own young, said Sigal Balshine, a behavioral ecologist at McMaster University in Ontario. Other males may sneak some of their own sperm onto the eggs.
In a 2012 study of plainfin midshipman fish, Dr. Balshine and her co-authors gave paternity tests to babies and found that only about half of the young in a nest belonged to the dad who was guarding it. There was a lot more hanky-panky going on, Dr. Balshine said.
The new study is the most comprehensive look yet at how parenting has evolved in fish, Dr. Balshine said. But it looked at only a small fraction of the worlds more than 30,000 fish species, and may not be a representative sample.
Dr. Benun Sutton agrees that the link between paternal care and external fertilization is an older, perhaps dusty hypothesis that her work revives. But if caring fish fathers were being cuckolded too often, she says, they would pass on their genes so sparsely that their behavior would die out altogether.
The puzzle of fish dads has long fascinated biologists, Dr. Balshine said.
When we humans think about parental care, we think immediately of moms holding newborn babies, she said. Its true that females are the primary caregivers across much of the animal kingdom, from mammals to birds to reptiles. Fish provide an intriguing counterexample.
Dr. Benun Sutton said fish illustrate that, under the right circumstances, either parents care can be critical. Theres no evolutionary rule that moms have to be the main providers a lesson we can apply to our own species, she said. There is a very important role for dads.
Excerpt from:
Happy Fathers Day to All the Fish Dads Underwater - The New York Times
- History of Evolution | Internet Encyclopedia of Philosophy - December 9th, 2016 [December 9th, 2016]
- Evolution - Bulbapedia, the community-driven Pokmon encyclopedia - December 12th, 2016 [December 12th, 2016]
- What is Evolution - explanation and definitions - December 21st, 2016 [December 21st, 2016]
- Evolution (2001 film) - Wikipedia - January 28th, 2017 [January 28th, 2017]
- EvolutionM.net - Mitsubishi Lancer Evolution | Reviews, News ... - February 1st, 2017 [February 1st, 2017]
- YMCA evolution continues at lake - Gaston Gazette - February 7th, 2017 [February 7th, 2017]
- Ivanka Trump's Beauty Evolution, From 1998 to Today Watch - Us Weekly - February 7th, 2017 [February 7th, 2017]
- Lumpy, hairy, toe-like fossil could reveal the evolution of molluscs - The Guardian - February 7th, 2017 [February 7th, 2017]
- How Evolution Alters Biological Invasions - ScienceBlog.com (blog) - February 7th, 2017 [February 7th, 2017]
- Cultural evolution and the mutilation of women - The Economist - February 7th, 2017 [February 7th, 2017]
- Late-night hosts on the evolution of Trump: 'Dickish to dictatorish' - The Guardian - February 7th, 2017 [February 7th, 2017]
- Gold's Gym Regina rebrands to become Evolution Fitness - Regina Leader-Post - February 7th, 2017 [February 7th, 2017]
- Incremental Versus Radical Innovation: A Response to Josh Swamidass on Evolution and Cancer - Discovery Institute - February 7th, 2017 [February 7th, 2017]
- Blockchain: Investment (R)Evolution For Developing Markets - Forbes - February 7th, 2017 [February 7th, 2017]
- See the Evolution of the Famed Porsche 911 in 7 Photos - WIRED - February 7th, 2017 [February 7th, 2017]
- Exhibition charts 500 years of evolution of robots - Phys.Org - February 7th, 2017 [February 7th, 2017]
- How evolution turned ordinary plants into ravenous meat-eaters - Wired.co.uk - February 7th, 2017 [February 7th, 2017]
- Are Evolution Fresh Drinks 'Poison'? - snopes.com - February 7th, 2017 [February 7th, 2017]
- Non-Chromosomal DNA Drives Tumor Evolution - The Scientist - February 8th, 2017 [February 8th, 2017]
- Chimpanzee feet allow scientists a new grasp on human foot evolution - Phys.Org - February 8th, 2017 [February 8th, 2017]
- 'Goldilocks' genes that tell the tale of human evolution hold clues to variety of diseases - Science Daily - February 8th, 2017 [February 8th, 2017]
- Pac-Man is Coming to 'The Sandbox Evolution' Next Week - Touch Arcade - February 9th, 2017 [February 9th, 2017]
- Chimpanzee feet allow scientists a new grasp on human foot ... - Science Daily - February 9th, 2017 [February 9th, 2017]
- Bacteria sleep, then rapidly evolve, to survive antibiotic treatments - Phys.Org - February 9th, 2017 [February 9th, 2017]
- Orangutan squeaks reveal language evolution, says study - BBC ... - BBC News - February 9th, 2017 [February 9th, 2017]
- Evolution gives rhyme its reason - Aurora News Register - February 9th, 2017 [February 9th, 2017]
- Deeper origin of gill evolution suggests 'active lifestyle' link in early vertebrates - Science Daily - February 9th, 2017 [February 9th, 2017]
- From Tara Palmer-Tomkinson to Cara Delevingne: the evolution of the It girl - The Guardian - February 10th, 2017 [February 10th, 2017]
- Banned TED Talk: Rupert Sheldrake The Science Delusion - Collective Evolution - February 10th, 2017 [February 10th, 2017]
- VOTD: Watch the Evolution of Keanu Reeves' Acting Career - /FILM - February 10th, 2017 [February 10th, 2017]
- Pokmon Go Eevee evolution: How to evolve Eevee into Vaporeon, Jolteon and Flareon with new names - Eurogamer.net - February 10th, 2017 [February 10th, 2017]
- Horse evolution bucks evolutionary theory - Science News - February 10th, 2017 [February 10th, 2017]
- Samsung's Chromebook Pro highlights the category's continued evolution - TechCrunch - February 10th, 2017 [February 10th, 2017]
- Scientists solve fish evolution mystery - Phys.Org - February 10th, 2017 [February 10th, 2017]
- Wildfire evolution forces Forest Service into new thinking - The Daily Progress - February 11th, 2017 [February 11th, 2017]
- How the horse can help us answer one of evolution's biggest questions - Raw Story - February 11th, 2017 [February 11th, 2017]
- A primer on Darwin Day: Some religious groups embrace 'Theistic evolution' - LancasterOnline - February 11th, 2017 [February 11th, 2017]
- Apple: Evolution of in-car audio tech moving at 'speed of sound ... - Times of India - February 11th, 2017 [February 11th, 2017]
- Mariska Hargitay's Evolution from '80s Glam to Law & Order: Special Victims Unit - TVOvermind - February 12th, 2017 [February 12th, 2017]
- Evolution of baseball from power to speed has left SBs behind ... - Chicago Sun-Times - February 12th, 2017 [February 12th, 2017]
- More order with less judgment: An optimal theory of the evolution of cooperation - Science Daily - February 12th, 2017 [February 12th, 2017]
- J. Albert C. Uy speaks on evolution, biodiversity in bellied flycatcher population - The College Reporter - February 12th, 2017 [February 12th, 2017]
- See the Evolution of Movie Magic With Every Oscar Winner for Visual Effects in History - Gizmodo - February 12th, 2017 [February 12th, 2017]
- Numerology: Here's What Your Name Says About You - Collective Evolution - February 13th, 2017 [February 13th, 2017]
- The Evolution of Valentine's Day - Inside Science News Service - February 13th, 2017 [February 13th, 2017]
- Why evolution may be tech billionaires' biggest enemy - The Week Magazine - February 13th, 2017 [February 13th, 2017]
- Community Viewpoint: Evolution, like gravity, is much more than theory it is a fact - Kdminer - February 13th, 2017 [February 13th, 2017]
- How the horse can help us answer one of evolution's biggest questions - Phys.Org - February 13th, 2017 [February 13th, 2017]
- How evolution alters biological invasions - Science Daily - February 13th, 2017 [February 13th, 2017]
- Cockeyed squid shines light on deep sea evolution - Christian Science Monitor - February 13th, 2017 [February 13th, 2017]
- Eye Evolution: A Closer Look - Discovery Institute - February 14th, 2017 [February 14th, 2017]
- Evolution always wins: University of Idaho video game uses mutating aliens to teach science concepts - The Spokesman-Review - February 14th, 2017 [February 14th, 2017]
- Geneticists track the evolution of parenting - Phys.Org - February 14th, 2017 [February 14th, 2017]
- How this cockeyed squid shines a light on deep sea evolution - Christian Science Monitor - February 14th, 2017 [February 14th, 2017]
- 4 Possible Roadmaps For macOS and iOS Evolution - The Mac Observer (blog) - February 15th, 2017 [February 15th, 2017]
- The Evolution of the Energy Capital of the World - Texas Monthly - February 15th, 2017 [February 15th, 2017]
- Humons presents an atypical dance evolution - Detroit Metro Times - February 15th, 2017 [February 15th, 2017]
- Pokemon Go Adds 80 Generation 2 Pokemon, New Evolution Items This Week - IGN - February 15th, 2017 [February 15th, 2017]
- Fossil discovery rewrites understanding of reproductive evolution ... - Science Daily - February 15th, 2017 [February 15th, 2017]
- 'X-Men: Evolution' Is the Gateway Drug of Comic Book Shows - Geek - February 16th, 2017 [February 16th, 2017]
- A cultural catch: Evolution of wooden halibut hooks carved by native ... - Science Daily - February 16th, 2017 [February 16th, 2017]
- Bremerton's Fitness Evolution now Planet Fitness - Kitsap Sun (blog) - February 16th, 2017 [February 16th, 2017]
- Eye Evolution: The Waiting Is the Hardest Part - Discovery Institute - February 16th, 2017 [February 16th, 2017]
- Evolution Of The Yeezy: 2009-2017 - HotNewHipHop - February 16th, 2017 [February 16th, 2017]
- Prebiotic evolution: Hairpins help each other out - Science Daily - February 16th, 2017 [February 16th, 2017]
- This 'Live Birth' Fossil Could Change Humanity's Understanding Of Evolution - Daily Caller - February 16th, 2017 [February 16th, 2017]
- Mysterious Ancient Stonehenge-Like Circles Found in Amazon Rainforest - Collective Evolution - February 16th, 2017 [February 16th, 2017]
- 'Pokemon Go': How to Evolve Poliwhirl Into Politoed - Heavy.com - February 17th, 2017 [February 17th, 2017]
- 'Pokemon Go': How to Evolve Slowpoke Into Slowbro or Slowking - Heavy.com - February 17th, 2017 [February 17th, 2017]
- 'Pokemon Go': How to Evolve Gloom Into Bellossom - Heavy.com - February 17th, 2017 [February 17th, 2017]
- Pokmon Go Dragon Scale - how to evolve Seadra into Kingdra and how to get the Dragon Scale - Eurogamer.net - February 17th, 2017 [February 17th, 2017]
- Pokmon Go Eevee evolution: How to evolve Eevee into Umbreon, Espeon, Vaporeon, Jolteon and Flareon with new ... - Eurogamer.net - February 17th, 2017 [February 17th, 2017]
- University of Pittsburgh guest speaker discloses evolution findings - UTA The Shorthorn - February 17th, 2017 [February 17th, 2017]
- 'Pokemon Go' Special Items: Drop Rates for Evolution Items & Berries at Pokestops - Heavy.com - February 17th, 2017 [February 17th, 2017]
- How Vedic Philosophy Influenced Nikola Tesla's Idea of 'Free Energy' - Collective Evolution - February 18th, 2017 [February 18th, 2017]
- Migration to America took long enough for evolution to happen on the way - Ars Technica - February 18th, 2017 [February 18th, 2017]
- How To Choose Your Eevee Evolution In 'Pokmon GO:' Umbreon And Espeon Edition - Forbes - February 18th, 2017 [February 18th, 2017]
- Evolution Items - IGN - February 18th, 2017 [February 18th, 2017]
- Congo River fish evolution shaped by intense rapids: Genomic study ... - Science Daily - February 18th, 2017 [February 18th, 2017]
- Pokmon Go - How to evolve, use Special Items, when to evolve or Power Up your Pokmon - Eurogamer.net - February 18th, 2017 [February 18th, 2017]