Reduction of gene flow. However, speciation might also happen in a population with no specific extrinsic barrier to gene flow. Imagine a situation in which a population extends over a broad geographic range, and mating throughout the population is not random.
The Internal Revenue Service places restrictions on how far back you can amend your tax return, regardless of whether you owed tax or received a refund. Filers must use Form 1040X to amend a return and should only file an amendment to report certain changes. You have three years from the due date of the original return or two years from when you paid tax owing to submit an amended return. A pen next to an income tax form.
1 When to file. 2  To claim a refund, you generally must file Form 1040X within three years from the date you filed your original tax return or within two years from the date you paid the tax, whichever is later. 3  Processing time.4  Normal processing time for amended returns is 8 to 12 weeks.ere are 10 tips from the Internal Revenue Service about amending your federal tax return: 1  When to amend a return. 2  You should file an amended return if you need to correct your filing status, number of dependents, total income, tax deductions or tax credits.