Editing Ontogeny (section)

=== Adulthood ===
[[Adult]]hood is the stage of when physical and intellectual maturity have been achieved and this differs between species.  In [[Human development (biology)|humans]], adulthood is thought to be around 20 or 21 years old and is the longest stage of life, but in all species it ends with death.<ref>{{Cite web |title=adulthood {{!}} Britannica |url=https://www.britannica.com/science/adulthood |access-date=2022-04-28 |website=www.britannica.com |language=en}}</ref>  In [[dog]]s, small breeds (e.g., [[Yorkshire Terrier]], [[Chihuahua (dog)|Chihuahua]], [[Cocker Spaniel]], etc.) physically mature faster than large breeds (e.g., [[St. Bernard (dog)|Saint Bernard]], [[Great Dane]], [[Golden Retriever]], etc.), so adulthood is reached anywhere from 12 to 24 months or 1 to 2 years.<ref>{{Cite web |date=October 22, 2021 |first=Jan |last=Reisen |title=How Long Does Puppyhood Last? |url=https://www.akc.org/expert-advice/puppy-information/how-long-does-puppyhood-last/ |access-date=2022-04-28 |website=American Kennel Club |language=en}}</ref>  In contrast, many insect species have long larval stages and the adult stage is only for reproduction.  The silkworm [[moth]]s don't have mouthparts and don't feed, so they have to consume enough food during the larval stage for energy to survive and mate.<ref name="Gilbert-2000-2" />

==== Senescence ====
[[Senescence]] is when cells stop dividing but don't die, but these cells can build up and cause problems in the body.  These cells can release substances that cause inflammation and can damage healthy nearby cells.<ref>{{Cite web |date=2011-02-02 |title=senescence |url=https://www.cancer.gov/publications/dictionaries/cancer-terms/def/senescence |access-date=2022-04-28 |work=NCI's Dictionary of Cancer Terms |publisher=National Cancer Institute |language=en}}</ref> Senescence can be induced by un-repaired DNA damage (e.g., from radiation,<ref>{{Cite journal |last1=Borrego-Soto |first1=Gissela |last2=Ortiz-López |first2=Rocío |last3=Rojas-Martínez |first3=Augusto |date=2015 |title=Ionizing radiation-induced DNA injury and damage detection in patients with breast cancer |journal=Genetics and Molecular Biology |volume=38 |issue=4 |pages=420–432 |doi=10.1590/S1415-475738420150019 |pmc=4763322 |pmid=26692152 }}</ref> old age, etc.) or other cellular stress<ref>{{cite journal |last1=Narita |first1=M |title=Cellular senescence and chromatin organisation |journal=British Journal of Cancer |date=March 2007 |volume=96 |issue=5 |pages=686–691 |doi=10.1038/sj.bjc.6603636 |pmid=17311013 |pmc=2360064 }}</ref> and also is the state of being old.<ref>{{Cite web |title=Definition of SENESCENCE |url=https://www.merriam-webster.com/dictionary/senescence |access-date=2022-04-28 |website=www.merriam-webster.com |language=en}}</ref>